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Advantages of Non-Video ICCDs
Princeton Instruments offers the broadest line of high performance intensified CCD detectors for gated spectroscopy and single photon detection. These thermoelectrically cooled detectors are capable of extremely low readout noise, the highest sensitivity, and a dynamic range up to 16 bits. Specially selected microchannel plate (MCP) image intensifiers offer synchronous electronic exposure (gating) in as little as 2 nanoseconds. over a dozen CCD array options. In either case, the cooled CCD array in combination with Princeton Instruments' low noise by temporal discrimination. For instance, in combustion research a pulsed laser probe is used to investigate the chemistry within a flame. Since the flame itself emits broadband light continuously, the total flame emission is much greater than the signal resulting from the laser probe (such as laser induced fluorescence or Raman). Fortunately, since the laser pulse is very short and the time at which it occurs is known, it is possible to gate for a few nanoseconds during the laser pulse, thus reducing the flame emission interference by a factor of 106 to 108. Using presently available image intensifiers and gate pulse generators, gate times as short as 2 nsec FWHM (full width at half maximum) optical gate times are possible. (As even faster shuttering is demonstrated in several leading laboratories, PI is in the process of improving gating speed, so contact the factory for the latest performance information.) Since the control is electronic, the shutter time can be made virtually as long as desired, so shutter times from 5 nsec up to many seconds can be conveniently implemented in one instrument setup. The electronic shutter on/off ratio is very high, typically 5 â 106 or greater. Because these are non video CCDs, the gating function can be triggered easily from any part of the experiment: the trigger does not have to be timed in relation to the video rate as is the case in electronically shuttered video rate CCD detectors. Furthermore, PI gate pulse generators are designed to minimize the delay between the trigger event and the gate opening. This is critical in experiments that operate asynchronously and do not provide a pretrigger, including some types of high power lasers that pulse with considerable jitter even when using a pretrigger. This requires triggering from the actual laser pulse, and delaying the light (usually by multiple reflections between mirrors or in an optical fiber) until the gate "opens". Since light travels about a foot per nanosecond, every extra nanosecond of gate delay is lost light intensity. PI pulse generator delays are

Image Intensified detectors

The Most Sensitive Detectors in the World
For over twenty years Princeton Instruments has been producing high performance intensified systems for scientific, industrial, and medical customers worldwide. These detectors are ideal for the study of combustion, laser ablation, reaction dynamics (kinetics), and other high speed phenomena using laser induced fluorescence or other techniques. With over 1,000 intensified systems already in the field, Princeton Instruments has shipped more cooled non video intensified CCD detectors in the last year than all other manufacturers combined. The reason for such large numbers of detectors is simple: sensitivity. The integrated ICCD provides fiber optic coupling, offering throughput of 2-10 times greater than lens systems. The lens based system offers several lens designs and

With over 1,000 intensified systems already in the field, Princeton Instruments has shipped more cooled non video intensified CCD detectors in the last year than all other manufactur ers combined.
electronics provides high sensitivity with a total readout noise of only a few electrons RMS.

High Speed Gating
Gating is probably the most important single advantage of the ICCD. It is the electronic shutter action produced by controlling the photocathode-to-MCP input voltage of the image intensifier. Gating allows the detection of low light level signals in the presence of interfering light sources of much greater energy

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Princeton Instruments


adjustable down to less than 25 nsec, and for special applications even shorter delays can be provided on special order.

Photocathode Spectral Range
The selection of photocathodes is more fully explained in the Intensified CCD Detectors section.PI offers a selection of Gen II and Gen IV (also called Gen III enhanced) image intensifiers, covering the entire visible and NIR spectral region. Gen II intensifiers are available with red enhanced, blue enhanced, and compromise red-blue enhanced photocathodes as stock items. Quantum efficiencies above 1% are attainable from about 160 nm to about 850 nm with quartz or suprasil windows. Intensifiers with MgF2 windows are also available with response in the 120-700 nm range. Unusually high QE response, 20-28% at peak, is available with intensifiers designed for "slow gate" operation. Gen IV intensifiers are available in the 400 - 900 nm region, and for the 800 - 1100 nm region. Some image intensifiers suffer from "iris effect" when gated. Iris effect is mostly a result of the distributed resistance and capacitance of the photocathode, causing the periphery of the photocathode to turn on before the center and vice versa on turn off. The usual solution to iris effect problems is to put a conductive underlay on the photocathode, but this reduces quantum efficiency. High QE intensifiers with low iris effect and without compromise are offered exclusively by PI. PI selects image intensifiers for minimum noise, negligible corona, highest gain, and longest operational and shelf life. In addition, because of our close relationships with most of the major intensifier manufacturers worldwide, we can usually provide state-of-the-art custom photocathodes. For special requirements contact the factory or your PI representative.

Signal Detection vs. Signal Measurement
Probably the most confusing aspect of ICCDs is the distinction between detection and measurement. ICCDs, particularly fiber coupled ICCDs, have the option of operating the intensifier at extremely high net gain, greatly intensifying the light reaching the CCD. Thus a

single photoelectron from the photocathode can produce a signal of 80 to 100 A/D units ("counts") with a readout noise of only 1 A/D unit, making it very easy to determine if a photoelectron event occurred. This is detection, and ICCDs excel at it. A more complete discussion of the effects of gain and noise on the detection of Princeton Instruments detector designs allow direct fiber-to-fiber single photoelec- coupling of intensifiers and CCDs. For magnification ratios other tron events is than 1, this is accomplished using a fiber optic taper, as shown. found in the To maximize the signal to noise ratio of following section of this catalog, Lens the data as the signal increases, the gain Coupled vs. Fiber Coupled ICCDs. of the ICCD should be reduced, allowing In many experimental applications, the the maximum number of photons to be importance of detection is that it allows captured within the dynamic range of the experimental system to be set up and the ICCD. Some ICCD vendors have used adjusted into operation. In the beginthis as an argument against high gain ning, the various elements of the experiICCDs, but it is a false argument for three ment are not optimized and the mere reasons: existence of an optical signal is a sign the experimenter is on the right track. Once · For maximum S/N, the available signal the experiment is optimized, there is should just fill the detector's dynamic often sufficient optical signal so that range. existence is no longer important, but · The experimental world often refuses quantization is. to provide enough signal to fill the As the magnitude of the signal indetector's dynamic range. creases, the photon shot noise of the If you need extreme gain (detection signal itself becomes more significant, mode) to set up and adjust the experiand soon becomes the dominant noise ment, then it follows that with a "lowsource in the experiment, even if a low gain-only" ICCD it will not be possible (or sensitivity ICCD is used. As this happens, at least it will be much more tedious) to the gain advantage of the high sensitivity get the experiment optimized enough to ICCD over other detectors, including use the low sensitivity settings. lower gain lens coupled ICCDs, diminNon video vs. Fast Scan ishes unless other factors such as gating ICCD play an important role in the experiment. The advantage of a high sensitivity ICCD In addition to non video ICCDs there is not that it provides a higher S/N are several fast scan (video rate) ICCDs ratio with a reasonably sized signal, but available on the market that are being that it allows the experiment to be offered for spectroscopic applications. optimized to the condition where there For a low level continuous signal the non is enough signal to measure. Of course, video detector has the advantage due to once you reach this state, you can adjust its longer exposure time, since S/N is the gain downward in the high sensitivroughly proportional to exposure time to ity ICCD and get higher dynamic range a power between 0.5 and 1. and even a slightly better S/N ratio than For measuring repetitive pulsed signals, a non video detector can integrate with a low gain ICCD.
The Leader in Spectroscopic Detection 41

Image intensified detection


a number of pulses directly on the CCD. This provides a reduction in the effective readout noise, which increases with the square root of the number of scans averaged, especially if low gain is employed. If the gain is set sufficiently high, thresholding can be done on a spectrum basis. With the ST-138 Detector Controller this is accomplished directly in hardware, providing a pseudo photon counting mode. Another advantage of the non video ICCD is its high dynamic range, as high as 65,000:1 with a 16 bit A/D. This is particularly important in experiments that have a highly variable total light output, where often the significant information is in ratios between regions of the scene or the total output itself. Consider a low quality video rate camera operating with an 8 bit readout where, to suppress the incidence of false detections due to the CCD readout noise, the gain is set at 5 "counts" per photoelectron. This results in only a 50:1 ratio of signals that will stay on scale, and the maximum S/N is limited to 7 by the photon shot noise. Worse yet, if the system has been preset so that half scale represents a nominal signal to allow for some variation in the experiment, then the signal is reduced to 26 photoelectrons for a maximum S/N of 5. Now consider instead a scientific detector with 16 bits of resolution, also set at 5 "counts" per photoelectron. The half scale signal of this detector is 6,500 photoelectrons for a S/N of about 80, allowing you to handle a signal up to 13,000 photoelectrons and still have equal performance to the fast scan ICCD on small signals (26 or 50 photoelectrons in the above example). This detector offers 256 times the signal handling range. Of course, these are probably not the most realistic settings for an actual low light level experiment. After all, if there were 6,500 photoelectrons available, you would probably get much better results with an unintensified CCD detector (unless you need gating). A much more reasonable setting would be to adjust the ICCD gain for 15 "counts" per photoelectron, putting the low end at the limit of photon counting, with a top signal at nearly 4,400 photoelectrons for a photon shot noise limitation of 66:1. This still offers 85 times more latitude for signal variation than a low quality video rate ICCD.
42 Princeton Instruments

Image Intensified detectors

Psuedo Photon Counting
Although single stage MCP intensifiers do not have enough internal gain to obtain a saturated pulse height distribution, they can still be operated in a "photon counting" mode (photoelectron counting). This is achieved when the photon flux is low enough that the probability of more than 1 photon per pixel is negligible. This is the equivalent of dead time in a single point photon counter. Of course a non video detector allows the spectral rate to be adjusted to compensate for varying flux levels. Under these circumstances, it is possible to threshold each spectrum and sum them in memory. For high spectral rates, the ST-138 Detector Controller incorporates this thresholding capability in hardware, using a preset lookup table. At slower spectral rates more accurate results are available by using centroid finding and summation over adjacent pixels before thresholding in software. In either method each spectrum, after thresholding, is a map of photoelectron events. These are then summed, spectrum by spectrum, to produce a map of the photon flux in units of photoelectron events.

Spatial Resolution
The spatial resolution of ICCD detectors is limited in most cases by the image intensifier resolution capabilities, not by the CCD. Gen II Proximity focused MCP intensifiers seldom exceed a limiting resolution of 30 line pairs per millimeter. This is a good match at 1:1 magnification to large pixel CCDs, in the 20-27 µm pixel range. By using fiber optic tapers or lenses, 25 mm diameter intensifiers are optimized to match other smaller pixel CCDs. The situation is different for the new Gen IV high resolution image intensifiers. These intensifiers are specified by the manufacturer to have greater than 50 line pairs per millimeter resolution, corresponding to a spot size on the order of 40 µms. That becomes a closer match to the resolution of the CCD, and clearly makes tapers less attractive. Further information on intensified CCD detectors is found in the next two sections of this catalog, Lens Coupled vs. Fiber Coupled ICCDs and Intensified CCD Detectors. The first discusses S/N and other issues of intensified detectors, and the second lists specific models available from Princeton Instruments.


Comparison of Lens Coupled & Fiber Coupled ICCD Detectors
Many potential ICCD users are confused about the relative merits of lens coupled and fiber optic coupled ICCDs. This paper compares many of the features of these detectors, concentrating on sensitivity and signal to noise ratio performance. Sensitivity and Signal to Noise Ratio
Sensitivity and signal to noise ratio performance are often confused in discussions of ICCD detectors, especially in advertising literature. This is unfortunate and sometimes misleading to potential users. The reason for the confusion is that over most of their dynamic range, the signal to noise ratios of both lens coupled and fiber coupled ICCDs are determined mostly by the photon statistics. This fact makes it tempting for vendors with only lens coupled ICCDs to claim there is no difference, or even that it is somehow "beneficial" (in S/N terms) to use a lens system with low throughput. But sensitivity is not the same as signal to noise at very low light levels (under 100 photons per pixel). At very low light levels, sensitivity is more closely related to gain. Basically, it is the ability to determine whether or not a photoelectron has been emitted from the photocathode within a pixel in a frame. Thus to consider sensitivity, we must consider the probability of detection and the probability of false detection (a false alarm). A false alarm occurs whenever the CCD readout noise exceeds the decision threshold. Random emission from the photocathode (called equivalent background illumination or EBI) is another false alarm source, from the user's perspective, but is not considered a false alarm in the sense that an EBI (photo)electron is still an electron and should be detected. EBI can be reduced by cooling the intensifier and is normally negligible in gated applications. CCD detectors generally have between 250,000 and 1,000,000 pixels. Thus to have a tolerably low probability of false alarm in an entire frame, the probability of false alarm per pixel must be very small. Assuming the readout noise to be Gaussian, the false alarm threshold must be many times the standard deviation of the readout noise. On the other hand, the pulse height distribution of the image intensifier is approximately exponential, as shown below in Figure 1, which means that a some of the photoelectrons give rise to a relatively small output light pulse. Figure 2 shows the probability of detection for two values of probability (0.1 and 0.01) of false alarm per frame, for a 576 â 384 element CCD detector, in a system with the effective CCD readout noise (including support electronics and A/D noise) set to one A/D unit. While the setting of an acceptable false alarm rate and probability of detection depends strongly on the experimental conditions, performance much worse than 90% detection probability and 10% probability of false alarm per frame is hard to justify as true detection. Figure 2 clearly shows that to attain this level of performance, an average gain of about 50 A/D units per photoelectron is required. Even with current intensifier technology, this level of gain is impossible to obtain in a lens coupled system using a single stage intensifier while still providing a reasonable image intensifier lifetime. Furthermore, to obtain excellent linearity, minimum decay time phosphors composed of rare earth materials are often necessary. Unfortunately these phosphors are 4-10 times less efficient and therefore produce even smaller signals in the CCD. While the superior coupling efficiency of the fiber coupled ICCD can still maintain good sensitivity, the lens coupled ICCD is further strained under such circumstances.

Image intensified detection

Lens Coupled ICCD Advantages and Disadvantages
Not all lens vs. fiber coupled ICCD decisions are based solely on sensitivity. Lens coupled ICCDs offer some conveniences that may outweigh the above sensitivity arguments in some cases. One of the chief conveniences of lens coupled ICCDs is the ability to use the detector as both a CCD and an ICCD by removing the intensifier. In addition to this modular ability, Princeton Instruments detectors offer cross-compatibility between lenses. The lens coupled system has the significant advantage that when the intensifier and lens are removed, the underlying CCD detector is a full performance CCD detector. The lens coupled ICCD also represents a cost effective way to add gating capability to an existing CCD detector if ultimate sensitivity is not required.
1 0.9 0.8 0.7

100

P(fa) = 0.1 P(fa) = 0.01

10

0.6 0.5 0.4 0.3 0.2 0.1 0

50

100

150

200

250

Figure 1. Pulse amplitude distribution from a straight channel MCP. Counts shown as a function of channel number.

0

10

20

30

40

50

60

70

80

90

100

Figure 2. Probability of detection at two different false alarm rates.
The Leader in Spectroscopic Detection 43


Since the intensifier of a lens coupled system is not in thermal contact with the CCD, there is generally no need to flush it with dry gas to prevent condensation. Lens coupled systems can also utilize air cooled CCD detectors, which can achieve temperatures as low as -45°C without the need for water circulation. Princeton Instruments has several types of lens couplers available at this time, each of which can be combined with several basic intensifier types and sizes. In combination with several different CCDs offered with lens coupled detectors, over 30 different models of lens coupled ICCD are available. This ensures that a system can be selected to meet your exact specifications without compromise. Princeton Instruments offers an f/1.2 relay lens system which provides the highest throughput of any lens coupled ICCD on the market today. With light transfer of over 10%, the f/1.2 lens, coupled to a back illuminated CCD is at the beginning of the single photoelectron detection region in Figure 2, with a sensitivity of up to 50 counts per photoelectron. Beware of statements given by some manufacturers claiming that a single photoelectron will produce 100,000 photons from the phosphor. This value, often used to justify the use of inefficient lens coupling, is too high by almost one order of magnitude even for efficient (but not linear) P-20 phosphors. This value is grossly exaggerated for fast phosphors. The lower light throughput of lens coupling (relative to fiber coupling) is claimed by some to be an advantage at medium light levels, on the grounds that it results in fewer A/D units per photoelectron, and consequently the detector can withstand more photons/pixel beDetector Features Single Photoelectron Detection Performance as a CCD Detector Compactness Intensifier Lifetime Ease of Reconfiguration Dynamic Range Photocathode Cooling "Chicken Wire" Pattern Intrascenic Dynamic Range Lowest CCD Temperature (low temp reduces dark charge)

fore saturating. Since the S/N ratio is presumably photon noise limited at medium light levels, this should allow higher signal to noise ratios to be achieved. While there is some truth to this argument, especially in cases where one needs to use the intensifier for gating, PI detectors provide better alternatives. By operating at higher light throughput (low f number lens coupled or fiber coupled), the opportunity exists to reduce the image intensifier gain by adjusting the MCP voltage. Operation at lower gain provides better linearity and far greater intensifier lifetime. By reducing the intensifier gain, the required output charge per photoelectron from the microchannel plate is reduced, which in turn prevents any gain reduction due to local discharge of the microchannel plate. It has been incorrectly argued that operating at higher gain increases the microchannel plate standing current and therefore the linearity. The fallacy here is that the gain, and therefore the output charge requirement, increases exponentially with the MCP voltage, but the standing current only increases linearly. Coupling lenses increase the stray light of the detector system, reducing the intrascenic dynamic range. This is especially important in systems that must detect small features in the presence of large backgrounds, such as emission from high temperature plasmas or LIF in combustion analysis. Operation of lens coupled ICCDs at very high gain results in significantly reduced intensifier life. For this reason, PI strongly recommends operation of lens coupled ICCDs with very low readout noise CCDs (slow scan scientific grade) if high sensitivity is important. PI normally
f/2.3 lens coupled

supplies lens coupled ICCDs this way, with the gain limited to a safe value. As previously stated, operation at these values does reduce the capability to operate in the single photoelectron detection mode.

Integrated Fiber Coupled
The integrated fiber coupled ICCD is the highest performance ICCD available. As discussed above, single photoelectron detection is possible with this ICCD. When sufficient light is available, the MCP voltage (and gain) may be reduced to allow higher dynamic range and greatly extended intensifier life. Furthermore, there is some evidence that the effective noise associated with the electron multiplication process in the MCP is increased at higher voltages. The integrated ICCD does not operate at these high voltages even when set to 50-80 counts/photoelectron, so it provides better output signal to noise ratio for a given signal than a lens coupled ICCD. This ICCD is very difficult to design as it requires optimum performance from various parameters that are naturally in conflict, i.e., clean driving signals to the CCD, low level video signals from the CCD, efficient cooling and thermostating, high voltage wiring, intensifier cooling mechanics, and thermal insulation requirements. Princeton Instruments was for many years the only company producing these types of detectors. In fiber coupled ICCD detectors the CCD and intensifier cannot be under vacuum. To prevent condensation, these detectors must be flushed with nitrogen gas or dry air during operation, or can be backfilled with nitrogen gas. Finally, whenever the CCD is cooled, water or air is used to dissipate the heat generated by the thermoelectric cooler.
Integrated fiber coupled good N/A good best N/A best to -20°C, lowest EBI More, software correctable best -45°C

Image Intensified detectors

f/1.2 lens coupled
to a back illuminated CCD fair best poor good good better Possible, not available least fair LN cooling (-120°C), lowest dark charge

to a front illuminated CCD poor best good poor (brand x) good (PI) good good Possible, not available least fair LN cooling (-120°C), lowest dark charge

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ICCD for Spectroscopy
Princeton Instruments offers eleven different detector models for spectroscopic applications, with four different gate pulse generators and numerous accessories and variations. These are described on the data sheets on the following pages. This section lists each model and gives a general overview of each detector. quires no nitrogen purging or liquid coolant. The CCD used is the EEV 1024 â 256, coupled to a 25 mm image intensifier. Because this detector is sealed the photocathode is not cooled, and there is an additional quartz window in front of the image intensifier. With only air circulation the achievable CCD temperature is somewhat warmer than for the same ICCD model. Model ITE/CCD-1024M This fiber coupled, sealed detector is the same as the previous model, only in this case an 18 mm image intensifier is used. Once again no nitrogen purging or liquid coolant is needed, but with the above limitations. Model ITE/CCD-576 This fiber coupled model is also a sealed detector, using 1:1 fiber optics to connect the EEV 576 â 384 CCD to an 18 mm image intensifier. This detector, like all ITE/CCD detectors, is compact and maintenance free, requiring only air circulation to achieve reasonable cooling of the CCD. Models ICCD/LCBI-512 & ICCD/LCBI-1024 These lens coupled detectors use back illuminated square format CCDs in a modular arrangement. The less efficient lens coupling is partially made up for by using high-QE, lownoise back illuminated CCD arrays. This results in a modular design which can be used intensified or unintensified. In addition, it allows better CCD cooling, including cryogenic cooling, for applications requiring very long integration times. ICCD-512 Kinetics This detector is designed to take a number of spectra and store them on the CCD in rapid succession. After this burst of data collection, the CCD is read out at normal rates. A movable mask defines the amount of CCD area allocated to light sensing vs. data storage. By moving the mask out of the way, this detector can also operate as a full frame ICCD detector. Lens-coupled Intensifiers for Detectors Made by Other Companies Based on our experience with image intensifiers and high performance relay lens systems, Princeton Instruments offers lens coupled intensifier systems for detectors made by other companies. All that is required is a C-mount or F-mount lens interface.

Pulsers
Model PG-200 Programmable Gate Pulse Generator The PG-200 is the highest performance model, capable of producing gate pulses from 3.5 nsec to 80 msec, all under computer control. It can also act as a frequency generator and as the source of timing for a complete system, providing several other triggers, before or after each gate pulse. Model FG-100 Gate Pulse Generator This model offers high speed gating, from 5 nsec to 2.5 microseconds. A special version is available that will allow gating in as little as 2 nsec. It can also act as the source of timing for other system components. Model FG-101 Built-In Gate Pulse Generator This is a gate pulse generator circuit card which can be installed inside an ICCD-576 detector head. It operates down to 5 nsec gate widths based on externally supplied TTL timing signals such as from a Stanford Research DG-535. Model PG-10 Gate Pulse Generator This economical pulser model provides pulse widths ranging from 180 nsec to 6 msec.

Detectors
Model ICCD-1024MLD This fiber coupled ICCD is based on an EEV 1024 â 256 full frame CCD and a 25 mm image intensifier. This detector offers the largest spectral coverage, high sensitivity, and good cooling of both the CCD and the photocathode. Model ICCD-1024M This fiber coupled ICCD is based on the same EEV 1024 â 256 CCD as above, only it uses an 18 mm intensifier. The same high sensitivity and good cooling are offered with this as with the previous model, but the spectral coverage is limited by the diameter of the image intensifier. Model ICCD-576LD-E This fiber coupled ICCD uses a 25 mm image intensifier and a fiber optic taper to connect to an EEV 576 â 384 full frame CCD. The taper matches the large size of the image intensifier to the size of the CCD, providing more spectral coverage than the 18 mm version below. Good cooling of both the CCD and the photocathode are provided. A vacuum ultraviolet option is available. Model ICCD-576E This fiber coupled ICCD uses an 18 mm image intensifier coupled using 1:1 fiber optics to the EEV 576 â 384 full frame CCD. The 1:1 fiber optics give high sensitivity and good cooling of both the CCD and the photocathode is achieved. Model ICCD-512T This fiber coupled model uses a square format CCD from Thomson with 512 â 512 pixel resolution coupled to an 18 mm image intensifier. This detector is useful for an application where both imaging and spectroscopic data are required. As with all ICCDs that use nitrogen flushing, cooling of both the CCD and the photocathode is provided. Model ITE/CCD-1024MLD This fiber coupled, sealed detector re-

Image intensified detection

Accessories and Options
Optical trigger: This option allows a PG-200 or FG-100 gate pulse generator to be triggered directly by an optical pulse through a fiber optic cable. MCP-100: This option adds a high voltage power supply to any of PI's gate pulse generator models. This allows them to operate ICCD models that do not have a high voltage supply built-in. IIC-100: This is a high voltage power supply for use with ICCD models that do not have high voltage built in and when gating is not required. CPC-100: Photocathode cooling accessory for the Model ICCD-576. It uses externally supplied refrigerated coolant to lower the temperature of the intensifier's photocathode to -20°C or lower. This lowers the photocathode dark current significantly, important for intensified CW operation.
The Leader in Spectroscopic Detection 45


High Performance Image Intensifiers
Princeton Instruments purchases hundreds of scientific image intensifiers each year, working with every major manufacturer worldwide. The most advanced photocathode technology is utilized to provide the highest possible QE. Because of our high volume, we are able to select intensifiers for individual customer requirements, often with delivery directly from our stock. All of our ICCD detectors are built with Gen II or Gen IV image intensifiers, based on fine pitch microchannel plates. Examples of some typical spectral responses are shown at right.
100 Blue Enhanced Gen IV
Quantum Efficiency, %

10 VUV Gen II 1 RB (better red), slow gate Gen II

NIR Gen IV

Image Intensified detectors

0.1 RB (better UV), slow gate Gen II 0.01 100 200 300 400 700 500 600 Wavelength, nm 800 900 1000 1100

Quantum Efficiency Gen II UV-NIR Enhanced (180-800 nm); 18 mm, 16% peak for 50 nsec gating, 13% peak for 5 nsec; 25 mm, 15% peak for 70 nsec, 11% peak for 5 nsec gating Gen II Super NIR Enhanced (360-920 nm); 10% at 500 nm, 8% at 800 nm Gen II VUV-Enhanced (120-600 nm); 8% at 120 nm Gen IV Blue Enhanced; 32% at 550 nm Gating 5 nsec FWHM (2-3 nsec rise time) for Gen II. 12 nsec for Gen IV. On/Off Ratio 5 x 106:1. Minimal iris effect is allowed, as a trade-off to enhance QE. Spatial Resolution 85 micron spot size FWHM, Gen II. 40-60 micron spot size FWHM, Gen IV. Linearity Better than 1% for the upper 95% of range. Slight, reproducible nonlinearity in lower 5% of intensity range. Phosphors with 1% linearity over the entire range are available. Phosphor Decay 2 msec standard, 300 nsec phosphor is optional Nonuniformity Typically 12% (18 mm), 16% (25 mm)

Gen II Photocathode Dark Defects 18 mm Quality area Contrast threshold > 300 microns 150-300 µm 80-150 µm 30-80 µm < 30 µm 10â14 mm 20% none none 6 < 25 no limit 25 mm 15 mm diam. 30% none 3 10 no limit no limit

Note: Since the point spread function of a Gen II intensifier is typically 75-85 µm FWHM, photocathode defects below this size are generally not visible

For CW applications it is strongly recommended that the photocathode be cooled as well. The PI CPC-100 cooled photocathode option reduces EBI by 5-10 times. The performance figures above are for intensifiers specifically selected for Princeton Instruments. Because they exceed standard Grade 1 performance, they are denoted Grade 1+. ICCD detectors with normal (Grade 1) intensifiers are available at lower cost. Grade 2 intensifiers are also offered in the 18 mm format. Defect-free intensifiers and CCD arrays (Grade 0) are available at a higher cost.

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ICCD Spectrometric Detectors
ICCD-1024MLD
These integrated, fiber-coupled, slowscan ICCD models, for both pulsed and CW operation, utilize a CCD with a full 25 mm spectral coverage. This EEV CCD has a 1024 â 256 format, fiber optically coupled to an image intensifier using 1:1 optics. Fiber optic coupling gives the highest sensitivity possible, with up to 80 counts per photoelectron. This allows single photoelectron detection, even at pixel rates as high as 1 MHz. The LD model uses a 25 mm intensifier. Even with a 25 mm intensifier not every pixel is illuminated, as indicated below. The 25 mm intensifier has a greater field of view but a slightly longer gate time than 18 mm models. This model is an integrated ICCD, where the high voltage power supply is built into the detector head. This model does not require the MCP-100 or IIC-100 high voltage supply. In this model the CCD is thermo-electrically cooled, with heat from the peltier stack dissipated to water or circulating coolant. Nitrogen gas flows over the CCD and intensifier. This prevents high voltage arcing and corona that can otherwise occur in humid atmospheres. In this design, the nitrogen passes first over the CCD region, where it is cooled. It then passes over the input window of the intensifier, cooling it in the process. This typically lowers the photocathode temperature by about 12° Centigrade, significantly lowering photocathode dark current in CW operation. Both gated and CW modes of operation are intensified. For CW operation, the intensifier acts as an electronic shutter, preventing light from reaching the CCD during readout.

Image intensified detection

CCD Array EEV Model 30-11, full frame CCD; front illuminated; MPP only; 1024 â 256 pixels (4:1 aspect ratio); 26 â 26 µm pixels Intensifier 25 mm diameter Method of Coupling 1:1 fiber optics Vignetting None, since coupling is fiber optic Field of View 23.5 â 6.7 mm, 900 â 256 pixels; In the center of the CCD over 940 pixels are illuminated Sensitivity Up to 80 counts/photoelectron (adjustable from 1-80)

Gating Speed 7 nsec FWHM for fast gate, 100 nsec FWHM for slow gate but with higher QE CCD Cooling Thermoelectric, down to -30°C with tap water, down to -40°C with 0°C coolant Photocathode Cooling About 12° centigrade below ambient by nitrogen flow Photocathode Dark Current (CW) Red-blue photocathode, <5 counts/ pixel-second; Red-enhanced photocathode, <15 counts/pixel-second CCD Read Noise < 1 counts RMS at 100 kHz; < 1.6 counts RMS at 1 MHz; both numbers assume 20 electrons/count A/D calibration

Spectroscopic Dynamic Range 16 bits at 100 kHz; 14 bits at 1 MHz Other CCD Specifications See page 17 for detailed specifications of the CCD performance not found here High Voltage Supply Integrated into the detector head Configurations Available E, EEV CCD array; M, AIMO (MPP) CCD; G, fast-gating; S, slow gating; RB, red-blue UV-NIR photocathode; RE, red-enhanced photocathode

The Leader in Spectroscopic Detection 47


ICCD Spectrometric Detectors
ICCD-1024M
These integrated, fiber-coupled, slowscan ICCD models, for both pulsed and CW operation, utilize a CCD with a full 25 mm spectral coverage. This EEV CCD has a 1024 â 256 format, fiber optically coupled to an image intensifier using 1:1 optics. Fiber optic coupling gives the highest sensitivity possible, with up to 80 counts per photoelectron. This allows single photoelectron detection, even at pixel rates as high as 1 MHz. This standard model uses an 18 mm intensifier. The 18 mm intensifier has a smaller field of view but a faster gate time than models with 25 mm intensifiers. This model is an integrated ICCD, where the high voltage power supply is built right into the detector head. This model does not require the MCP-100 or IIC-100 high voltage supply. In this model the CCD is thermo-electrically cooled, with heat from the peltier stack dissipated to water or circulating coolant. Nitrogen gas flows over the CCD and intensifier. This prevents high voltage arcing and corona that can otherwise occur in humid atmospheres. In this design, the nitrogen passes first over the CCD region, where it is cooled. It then passes over the input window of the intensifier, cooling it in the process. This typically lowers the photocathode temperature by about 12° Centigrade, significantly lowering photocathode dark current in CW operation. Both gated and CW modes of operation are intensified. For CW operation, the intensifier acts as an electronic shutter, preventing light from reaching the CCD during readout.

Image Intensified detectors

CCD Array EEV Model 30-11, full frame CCD; front illuminated; MPP only; 1024 â 256 pixels (4:1 aspect ratio); 26 â 26 µm pixels Intensifier 18 mm diameter Method of Coupling 1:1 fiber optics Vignetting None, since coupling is fiber optic Field of View 16.1 â 6.7 mm, 620 â 256 pixels; In the center of the CCD over 670 pixels are illuminated Sensitivity Up to 80 counts/photoelectron (adjustable from 1-80)

Gating Speed 5 nsec FWHM for fast gate, 50 nsec FWHM for slow gate but with higher QE CCD Cooling Thermoelectric, down to -30°C with tap water, down to -40°C with 0°C coolant Photocathode Cooling About 12° centigrade below ambient by nitrogen flow Photocathode Dark Current (CW) Red-blue photocathode, < 5 counts/ pixel-second; Red-enhanced photocathode, < 15 counts/pixel-second CCD Read Noise < 1 counts RMS at 100 kHz; < 1.6 counts RMS at 1 MHz; both numbers assume 20 electrons/count A/D calibration

Spectroscopic Dynamic Range 16 bits at 100 kHz; 14 bits at 1 MHz Other CCD Specifications See page 17 for detailed specifications of the CCD performance not found here High Voltage Supply Integrated into the detector head Configurations Available E, EEV CCD array; M, AIMO (MPP) CCD; G, fast-gating; S, slow gating; RB, red-blue UV-NIR photocathode; RE, red-enhanced photocathode

48

Princeton Instruments


ICCD Spectrometric Detectors
ICCD-576LD-E
This integrated, fiber-coupled, slowscan ICCD model, for both pulsed and CW operation, is our most popular 25 mm model. It uses an EEV 576 â 384 CCD, fiber optically coupled to an image intensifier. Fiber optic coupling gives the highest sensitivity possible, with up to 35 counts per photoelectron. This allows single photoelectron detection, even at pixel rates as high as 1 MHz. The LD model uses a fiber optic taper to couple the CCD to a large diameter (25 mm) intensifier. This gives improved spatial resolution and a large field of view. This model is an integrated ICCD, where the high voltage power supply is built right into the detector head. This model does not require the MCP-100 or IIC-100 high voltage supply. In this model the CCD is thermoelectrically cooled, with heat from the peltier stack dissipated to water or circulating coolant. Nitrogen gas flows over the CCD and intensifier. This prevents high voltage arcing and corona that can otherwise occur in humid atmospheres. In this design, the nitrogen passes first over the CCD region, where it is cooled. It then passes over the input window of the intensifier, cooling it in the process. This typically lowers the photocathode temperature by about 12° Centigrade, significantly lowering photocathode dark current in CW operation. Further cooling can be achieved with our CPC-100 option, described on page 63. Both gated and CW operation are intensified. For CW operation, the intensifier acts as an electronic shutter, preventing light from reaching the CCD during readout.

Image intensified detection

CCD Array EEV Model 02-06, full frame CCD; front illuminated; standard or AIMO (MPP); 576 â 384 pixels (3:2 aspect ratio); 22.5 â 22.5 µm pixels Intensifier 25 mm diameter Method of Coupling 1.5:1 fiber optic reducer Vignetting None, since coupling is fiber optic Field of View 19.3 â 12.9 mm (23.2 mm diagonal) Sensitivity Up to 35 counts/photoelectron (adjustable from 1-35) Gating Speed 7 nsec FWHM for fast gate, 100 nsec FWHM for slow gate but with higher QE

CCD Cooling Thermoelectric, down to -35°C with tap water, down to -45°C with 0°C coolant Photocathode Cooling About 12° centigrade below ambient by nitrogen flow; Below -20°C with CPC-100 option (page 63) Photocathode Dark Current (CW) Red-blue photocathode, <5 counts/ pixel-second; Red-enhanced photocathode, <15 counts/pixel-second CCD Read Noise < 1.3 counts RMS at 100 kHz; < 2 counts RMS at 1 MHz; both numbers assume 15 electrons/count A/D calibration Spectroscopic Dynamic Range 16 bits at 100 kHz; 14 bits at 1 MHz

Other CCD Specifications See page 21 for detailed specifications of the CCD performance not found here High Voltage Supply Integrated into the detector head Configurations Available E, EEV CCD array; M, AIMO (MPP) CCD option; G, fast-gating; S, slow gating; RB, red-blue UV-NIR photocathode; RE, red-enhanced photocathode; IVUV intensified vacuum ultraviolet

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ICCD Spectrometric Detectors
ICCD-576E · RE/ICCD-576E
This integrated, fiber-coupled, slowscan ICCD model, for both pulsed and CW operation, is our most popular model with hundreds installed worldwide. It uses an EEV 576 â 384 CCD, fiber optically coupled to an image intensifier. Fiber optic coupling gives the highest sensitivity possible, with up to 80 counts per photoelectron. This allows single photoelectron detection, even at pixel rates as high as 1 MHz. The standard model uses 1:1 fiber optic coupling to an 18 mm image intensifier. This coupling provides the highest number of counts per photoelectron, and efficiently matches the size of the image intensifier to the CCD. This model is an integrated ICCD, where the high voltage power supply is built right into the detector head. This model does not require the MCP-100 or IIC-100 high voltage supply. In this model the CCD is thermoelectrically cooled, with heat from the peltier stack dissipated to water or circulating coolant. Nitrogen gas flows over the CCD and intensifier. This prevents high voltage arcing and corona that can otherwise occur in humid atmospheres. In this design, the nitrogen passes first over the CCD region, where it is cooled. It then passes over the input window of the intensifier, cooling it in the process. This typically lowers the photocathode temperature by about 12° Centigrade, significantly lowering photocathode dark current in CW operation. Further cooling can be achieved with our CPC-100 option, described on page 63. Both gated and CW operation are intensified. For CW operation, the intensifier acts as an electronic shutter, preventing light from reaching the CCD during readout.

Image Intensified detectors

CCD Array EEV Model 02-06, full frame CCD; front illuminated; standard or AIMO (MPP); 576 â 384 pixels (3:2 aspect ratio); 22.5 â 22.5 µm pixels Intensifier 18 mm diameter Method of Coupling 1:1 fiber optics Vignetting None, since coupling is fiber optic Field of View 12.9 â 8.6 mm (15.5 mm diagonal) Sensitivity Up to 80 counts/photoelectron (adjustable from 1-80) Gating Speed 5 nsec FWHM for fast gate, 50 nsec FWHM for slow gate but with higher QE

CCD Cooling Thermoelectric, down to -35°C with tap water, down to -45°C with 0°C coolant Photocathode Cooling About 12° centigrade below ambient by nitrogen flow; Below -20°C with CPC-100 option (page 63) Photocathode Dark Current (CW) Red-blue photocathode, < 5 counts/ pixel-second; Red-enhanced photocathode, < 15 counts/pixel-second CCD Read Noise < 1.3 counts RMS at 100 kHz; < 2 counts RMS at 1 MHz; both numbers assume 15 electrons/count A/D calibration

Spectroscopic Dynamic Range 16 bits at 100 kHz; 14 bits at 1 MHz Other CCD Specifications See page 21 for detailed specifications of the CCD performance not found here High Voltage Supply Integrated into the detector head Configurations Available E, EEV CCD array; M, AIMO (MPP) CCD option; G, fast-gating; S, slow gating; RB, red-blue UV-NIR photocathode; RE, red-enhanced photocathode; IVUV intensified vacuum ultraviolet

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Princeton Instruments


ICCD Spectrometric Detectors
ICCD-512T
This integrated, fiber-coupled, slowscan ICCD model, for both pulsed and CW operation, is popular for customers who want a square format ICCD that can be used for both imaging and spectroscopic applications. It uses a Thomson 512 â 512 CCD, fiber optically coupled to an image intensifier. Fiber optic coupling gives the highest sensitivity possible, with up to 80 counts per photoelectron. This allows single photoelectron detection, even at pixel rates as high as 1 MHz. The standard model uses 1.2:1 fiber optic coupling to an 18 mm image intensifier. This coupling provides the highest CCD Array Thomson Model 7895, full frame CCD; front illuminated; MPP only; 512 â 512 pixels (1:1 aspect ratio); 19 â 19 µm pixels Intensifier 18 mm diameter Method of Coupling 1.2:1 fiber optic reducer Vignetting None, since coupling is fiber optic Field of View 12 â 12 mm (16.9 mm diagonal) Sensitivity Up to 80 counts/photoelectron (adjustable from 1-80) number of counts per photoelectron, and efficiently matches the size of the image intensifier to the CCD. This model is an integrated ICCD, where the high voltage power supply is built right into the detector head. This model does not require the MCP-100 or IIC-100 high voltage supply. In this model the CCD is thermoelectrically cooled, with heat from the peltier stack dissipated to water or circulating coolant. Nitrogen gas flows over the CCD and intensifier. This prevents high voltage arcing and corona that can otherwise occur in humid atmospheres. In this design, the nitrogen passes first Gating Speed 5 nsec FWHM for fast gate, 50 nsec FWHM for slow gate but with higher QE CCD Cooling Thermoelectric, down to -35°C with tap water, down to -45°C with 0°C coolant Photocathode Cooling About 12° centigrade below ambient by nitrogen flow; Below -20°C with CPC-100 option (page 63) Photocathode Dark Current (CW) Red-blue photocathode, < 5 counts/ pixel-second; Red-enhanced photocathode, < 15 counts/pixel-second over the CCD region, where it is cooled. It then passes over the input window of the intensifier, cooling it in the process. This typically lowers the photocathode temperature by about 12° Centigrade, significantly lowering photocathode dark current in CW operation. Further cooling can be achieved with our CPC-100 option, described on page 63. Both gated and CW operation are intensified. For CW operation, the intensifier acts as an electronic shutter, preventing light from reaching the CCD during readout.

Image intensified detection

CCD Read Noise < 1.3 counts RMS at 100 kHz; < 2 counts RMS at 1 MHz; both numbers assume 15 electrons/count A/D calibration Spectroscopic Dynamic Range 16 bits at 100 kHz; 14 bits at 1 MHz High Voltage Supply Integrated into the detector head Configurations Available M, AIMO (MPP) CCD option; G, fast-gating; S, slow gating; RB, red-blue UV-NIR photocathode; RE, red-enhanced photocathode; IVUV intensified vacuum ultraviolet

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ICCD Spectrometric Detectors
ITE/CCD-1024MLD
This compact, fiber-coupled ICCD is designed to optimize ease of use. It is a sealed detector, requiring no purge gas, and it uses forced air to dissipate heat instead of water flow. As a sealed system, no nitrogen flow is required. The detector is filled and sealed at the factory, and no further purging should be required. Although this is an added convenience it does lose the advantage of cathode cooling by the flowing nitrogen purge gas. As a result, in CW mode there is increased dark current over that which would be present in a purged detector. Researchers only planning pulsed work will find this an acceptable tradeoff. As an air cooled system the ITE/CCD requires no water coolant. This results in a slightly higher CCD temperature and thus higher CCD dark charge. Researchers who are only planning short exposure times (those not integrating over many pulses) will find this an acceptable tradeoff. To make the detector head more compact, this model does not contain an internal high voltage supply. The MCP100 or IIC-100 must be purchased to operate this detector. This design uses an EEV 1024 â 256 CCD, fiber optically coupled to a 25 mm image intensifier. Fiber optic coupling gives the highest sensitivity possible, allowing single photoelectron detection, even at pixel rates as high as 1 MHz. Nearly all pixels are illuminated by the intensifier in the center of the CCD, some pixels in the corner are not illuminated. In this model, both gated and CW operation are intensified. For CW operation, the intensifier acts as an electronic shutter, preventing light from reaching the CCD during readout.

Image Intensified detectors

CCD Array EEV Model 30-11, full frame CCD; front illuminated; MPP only; 1024 â 256 pixels (4:1 aspect ratio); 26 â 26 µm pixels Intensifier 25 mm diameter Method of Coupling 1:1 fiber optics Vignetting None, since coupling is fiber optic Field of View 23.5 â 6.7 mm, 900 â 256 pixels; In the center of the CCD over 940 pixels are illuminated Sensitivity Up to 80 counts/photoelectron (adjustable from 1-80)

Gating Speed 7 nsec FWHM for fast gate, 100 nsec FWHM for slow gate but with higher QE CCD Cooling Thermoelectric, down to -25°C with forced air circulation Photocathode Cooling None Photocathode Dark Current (CW) Red-blue photocathode, < 10 counts/ pixel-second; Red-enhanced photocathode, < 30 counts/pixel-second CCD Read Noise < 1 counts RMS at 100 kHz; < 1.6 counts RMS at 1 MHz; both numbers assume 20 electrons/count A/D calibration

Spectroscopic Dynamic Range 16 bits at 100 kHz; 14 bits at 1 MHz Other CCD Specifications See page 17 for detailed specifications of the CCD performance not found here High Voltage Supply External, uses the MCP-100 option on a Princeton Instruments PG-200, FG-100, or PG-10 gate pulse generator, or an IIC-100 Image Intensifier Controller unit Configurations Available M, AIMO (MPP) CCD option; G, fast-gating; S, slow gating; RB, red-blue UV-NIR photocathode; RE, red-enhanced photocathode

52

Princeton Instruments


ICCD Spectrometric Detectors
ITE/CCD-1024M
This compact, fiber-coupled ICCD is designed to optimize ease of use. It is a sealed detector, requiring no purge gas, and it uses forced air to dissipate heat instead of water flow. As a sealed system, no nitrogen flow is required. The detector is filled and sealed at the factory, and no further purging should be required. Although this is an added convenience it does lose the advantage of cathode cooling by the flowing nitrogen purge gas. As a result, in CW mode there is increased dark current over that which would be present in a purged detector. Researchers only planning pulsed work will find this an acceptable tradeoff. As an air cooled system the ITE/CCD requires no water coolant. This results in a slightly higher CCD temperature and thus higher CCD dark charge. Researchers who are only planning short exposure times (those not integrating over many pulses) will find this an acceptable tradeoff. To make the detector head more compact, this model does not contain an internal high voltage supply. The MCP-100 or IIC-100 must be purchased to operate this detector. This design uses an EEV 1024 â 256 CCD, fiber optically coupled to an 18 mm image intensifier. Fiber optic coupling gives the highest sensitivity possible, allowing single photoelectron detection, even at pixel rates as high as 1 MHz. Not all pixels are illuminated by the intensifier. In this model, both gated and CW operation are intensified. For CW operation, the intensifier acts as an electronic shutter, preventing light from reaching the CCD during readout.

Image intensified detection

CCD Array EEV Model 30-11, full frame CCD; front illuminated; MPP only; 1024 â 256 pixels (4:1 aspect ratio); 26 â 26 µm pixels Intensifier 18 mm diameter Method of Coupling 1:1 fiber optics Vignetting None, since coupling is fiber optic Field of View 16.1 â 6.7 mm, 620 â 256 pixels; In the center of the CCD over 670 pixels are illuminated Sensitivity Up to 80 counts/photoelectron (adjustable from 1-80)

Gating Speed 5 nsec FWHM for fast gate, 50 nsec FWHM for slow gate but with higher QE CCD Cooling Thermoelectric, down to -25°C with forced air circulation Photocathode Cooling None Photocathode Dark Current (CW) Red-blue photocathode, < 10 counts/ pixel-second; Red-enhanced photocathode, < 30 counts/pixel-second CCD Read Noise < 1 counts RMS at 100 kHz; < 1.6 counts RMS at 1 MHz; both numbers assume 20 electrons/count A/D calibration

Spectroscopic Dynamic Range 16 bits at 100 kHz; 14 bits at 1 MHz Other CCD Specifications See page 17 for detailed specifications of the CCD performance not found here High Voltage Supply External, uses the MCP-100 option on a Princeton Instruments PG-200, FG-100, or PG-10 gate pulse generator, or an IIC-100 Image Intensifier Controller unit Configurations Available M, AIMO (MPP) CCD option; G, fast-gating; S, slow gating; RB, red-blue UV-NIR photocathode; RE, red-enhanced photocathode

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ICCD Spectrometric Detectors
ITE/CCD-576
This compact, fiber-coupled ICCD is designed to optimize ease of use. It is a sealed detector, requiring no purge gas, and it uses forced air to dissipate heat instead of water flow. As a sealed system, no nitrogen flow is required. The detector is filled and sealed at the factory, and no further purging should be required. Although this is an added convenience it does lose the advantage of cathode cooling by the flowing nitrogen purge gas. As a result, in CW mode there is increased dark current over that which would be present in a purged detector. Researchers only planning pulsed work will find this an acceptable tradeoff. As an air cooled system the ITE/CCD requires no water coolant. This results in a slightly higher CCD temperature and thus higher CCD dark charge. Researchers who are only planning short exposure times (those not integrating over many pulses) will find this an acceptable tradeoff. To make the detector head more compact, this model does not contain an internal high voltage supply. The MCP-100 or IIC-100 must be purchased to operate this detector. This design uses an EEV 576 â 384 CCD, fiber optically coupled to an 18 mm image intensifier. Fiber optic coupling gives the highest sensitivity possible, allowing single photoelectron detection, even at pixel rates as high as 1 MHz. In this model, both gated and CW operation are intensified. For CW operation, the intensifier acts as an electronic shutter, preventing light from reaching the CCD during readout.

Image Intensified detectors

The Model ITE/CCD-576

CCD Array EEV Model 02-06, full frame CCD; front illuminated; standard or AIMO (MPP); 576 â 384 pixels (3:2 aspect ratio); 22.5 â 22.5 µm pixels Intensifier 18 mm diameter Method of Coupling 1:1 fiber optics Vignetting None, since coupling is fiber optic Field of View 12.9 â 8.6 mm (15.5 mm diagonal) Sensitivity Up to 80 counts/photoelectron (adjustable from 1-80)

Gating Speed 5 nsec FWHM for fast gate, 50 nsec FWHM for slow gate but with higher QE CCD Cooling Thermoelectric, down to -25°C with forced air circulation Photocathode Cooling None Photocathode Dark Current (CW) Red-blue photocathode, < 10 counts/ pixel-second; Red-enhanced photocathode, < 30 counts/pixel-second CCD Read Noise < 1.3 counts RMS at 100 kHz; < 2 counts RMS at 1 MHz; both numbers assume 15 electrons/count A/D calibration

Spectroscopic Dynamic Range 16 bits at 100 kHz; 14 bits at 1 MHz Other CCD Specifications See page 21 for detailed specifications of the CCD performance not found here High Voltage Supply External, uses the MCP-100 option on a Princeton Instruments PG-200, FG-100, or PG-10 gate pulse generator, or an IIC-100 Image Intensifier Controller unit Configurations Available M, AIMO (MPP) CCD option; G, fast-gating; S, slow gating; RB, red-blue UV-NIR photocathode; RE, red-enhanced photocathode

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Princeton Instruments


ICCD Spectrometric Detectors
LC/ICCD-1024SB
These systems couple the output of an image intensifier to a back illuminated CCD with a specially designed system of relay lenses. Lens coupling allows the intensifier to be removed so that, for CW operation, the detector can be used either with or without the intensifier. Also if two lenses are ordered, they can be easily interchanged. The array used in this detector is a SITe back illuminated 1024 â 1024 CCD. It provides a square format with a larger number of pixels than our fiber coupled models, and is ideal for use with both imaging and spectroscopic work. Standard 18 mm or 25 mm intensifiers are offered and larger models are available, see below. CCD Array SITe Model ST-003 BA; full frame CCD, back illuminated; MPP only; 1024 â 1024 pixels; 24 â 24 µm pixels Intensifier 18 or 25 mm diameter standard; contact the factory for special order 40 mm or 75 mm intensifiers Method of Coupling Relay lens system; 1:1 reduction factor, f/1.2; or 1.7:1 reduction factor, f/1.8 Vignetting Edge brightness with 1.0 reduction lens and 18 mm intensifier is 42% of center, with 25 mm intensifier it is 22% of center; Edge brightness with 1.7 re-duction lens and 18 mm intensifier is 68% of center, with 25 mm intensifier it is 48% of center. For all lenses, vignetting can be reduced by using a smaller aperture, at a reduction in throughput. Overall nonuniformity is a combination of vignetting in the lens system and nonuniformity of the intensifier. Uniformity in a lens coupled ICCD is primarily dependent on uniformity of gain, not uniformity of QE (which is quite good). These effects can be corrected through PI software. CW operation with the intensifier provides higher gain and thus a low minimum detectable signal, particularly in the blue and UV. CW operation without the intensifier provides higher quantum efficiency (particularly in the red) but comes at the expense of gain. Operation without an intensifier also offers higher spatial resolution. This system offers both modes of operation, making it particularly flexible. Of course for pulsed work, the intensifier must be used, as it is the time resolving element of the system. In general, lens coupling offers 6-10 times lower throughput from the intensifier to the CCD than fiber optic coupling. This can be partially offset by the high quantum efficiency of a back illuminated CCD at the wavelengths emitted by an intensifier. Lens coupling also provides complete thermal isolation between the intensifier and the CCD. Although the photocathode is no longer cooled indirectly through the CCD, this configuration allows much better CCD cooling, particularly when using a cryogenically cooled CCD. Cryogenically cooled detectors allow many thousands of gate pulses to be summed on the CCD. Because of its modularity, this model does not contain an internal high voltage supply. The MCP-100 or IIC-100 must be purchased to operate this detector.

Image intensified detection

Field of View 1:1 lens system, 24.5 â 24.5 mm (34.7 mm diagonal). Values above are the field of view at the CCD. Where the intensifier does not fill the active area of the CCD, portions of the CCD may not see light. Sensitivity 1:1 lens system, up to 50 counts/ photoelectron in the center; 1.7:1 lens system, up to 15 counts/photoelectron in the center Gating Speed 18 mm intensifier, 5 nsec fast gate, 50 nsec FWHM gate but with higher QE; intensifier, 7 nsec FWHM 100 nsec FWHM for slow Photocathode Cooling None Photocathode Dark Current (CW) Red-blue photocathode, < 10 counts/ pixel-second; Red-enhanced photocathode, < 30 counts/pixel-second

Other CCD Specifications See page 24 for detailed specifications of the CCD performance not found here High Voltage Supply External, uses the MCP-100 option on a Princeton Instruments PG-200, FG-100, or PG-10 gate pulse generator, or an IIC-100 Image Intensifier Controller unit Configurations Available TE/CCD, thermoelectrically cooled CCD detector base; LN/CCD, liquid nitrogen cooled detector base; RL/1:1, relay lens for 1:1 coupling; RL/1.7:1, relay lens system for 1.7:1 coupling; MCP-18, 18 mm intensifier in housing; MCP-25, 25 mm intensifier in housing; G, fast gating; S, slow gating; B, back illuminated CCD; RB, red-blue UV-NIR photocathode response; RE, red-enhanced response

FWHM for for slow 25 mm for fast gate, gate

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ICCD Spectrometric Detectors
LC/ICCD-512SB
These systems couple the output of an image intensifier to a back illuminated CCD with a specially designed system of relay lenses. Lens coupling allows the intensifier to be removed so that, for CW operation, the detector can be used either with or without the intensifier. Also if two lenses are ordered, they can be easily interchanged. The array used in this detector is a SITe back illuminated 512 â 512 CCD. It provides a square format with a larger number of pixels than our fiber coupled models, and is ideal for use with both imaging and spectroscopic work. Standard 18 mm or 25 mm intensifiers are offered and larger models are available, see below. CCD Array SITe Model 502 BA; full frame CCD, back illuminated; MPP only; 512 â 512 pixels; 24 â 24 µm pixels Intensifier 18 or 25 mm diameter standard; contact the factory for special order 40 mm or 75 mm intensifiers Method of Coupling Relay lens system; 1:1 reduction factor, f/1.2; or 1.7:1 reduction factor, f/1.8 Vignetting Edge brightness with 1.0 reduction lens and 18 mm intensifier is 42% of center, with 25 mm intensifier it is 22% of center; Edge brightness with 1.7 reduction lens and 18 mm intensifier is 68% of center, with 25 mm intensifier it is 48% of center. For all lenses, vignetting can be reduced by using a smaller aperature, at a reduction in throughput. Overall nonuniformity is a combination of vignetting in the lens system and nonuniformity of the intensifier. Uniformity in a lens coupled ICCD is primarily dependent on uniformity of gain, not uniformity of QE (which is quite good). These effects can be corrected through PI software. CW operation with the intensifier provides higher gain and thus a low minimum detectable signal, particularly in the blue and UV. CW operation without the intensifier provides higher quantum efficiency (particularly in the red) but comes at the expense of gain. Operation without an intensifier also offers higher spatial resolution. This system offers both modes of operation, making it particularly flexible. Of course for pulsed work, the intensifier must be used, as it is the time resolving element of the system. In general, lens coupling offers 6-10 times lower throughput from the intensifier to the CCD than fiber optic coupling. This can be partially offset Field of View 1:1 lens system, 12.2 â 12.2 mm (17.3 mm diagonal), 1.7:1 lens system, 20.8 â 20.8 mm (29.5 mm diagonal). Values above are the field of view at the CCD. Where the intensifier does not fill the active area of the CCD, portions of the CCD may not see light. Sensitivity 1:1 lens system, up to 50 counts/ photoelectron in the center; 1.7:1 lens system, up to 15 counts/photoelectron in the center Gating Speed 18 mm intensifier, 5 nsec FWHM for fast gate, 50 nsec FWHM for slow gate but with higher QE; 25 mm intensifier, 7 nsec FWHM for fast gate, 100 nsec FWHM for slow gate Photocathode Cooling None Photocathode Dark Current (CW) Red-blue photocathode, < 10 counts/ pixelsecond; Red-enhanced photocathode, < 30 counts/pixel-second Other CCD Specifications See page 22 for detailed specifications of the CCD performance not found here by the high quantum efficiency of a back illuminated CCD at the wavelengths emitted by an intensifier. Lens coupling also provides complete thermal isolation between the intensifier and the CCD. Although the photocathode is no longer cooled indirectly through the CCD, this configuration allows much better CCD cooling, particularly when using a cryogenically cooled CCD. Cryogenically cooled detectors allow many thousands of gate pulses to be summed on the CCD. Because of its modularity, this model does not contain an internal high voltage supply. The MCP-100 or IIC-100 must be purchased to operate this detector.

Image Intensified detectors

High Voltage Supply External, uses the MCP-100 option on a Princeton Instruments PG-200, FG-100, or PG-10 gate pulse generator, or an IIC-100 Image Intensifier Controller unit Configurations Available TE/CCD, thermoelectrically cooled CCD detector base; LN/CCD, liquid nitrogen cooled detector base; RL/1:1, relay lens for 1:1 coupling; RL/1.7:1, relay lens system for 1.7:1 coupling; MCP-18, 18 mm intensifier in housing; MCP-25, 25 mm intensifier in housing; G, fast gating; S, slow gating; B, back illuminated CCD; RB, red-blue UV-NIR photocathode response; RE, red-enhanced response

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ICCD Spectrometric Detectors
ICCD-512 Kinetics
The Kinetics ICCD detector from Princeton Instruments represents another of a long line of specialized intensified detector developed in response to customer needs. In kinetics mode, a spectrum is projected on a narrow strip at one end of a CCD and the rest of the CCD is masked and used as a storage area. Depending on the size of the open area, tens or even a few hundred spectra can be acquired in rapid succession. To do this on an ICCD, the photocathode on the intensifier must be masked. For an intensified detector that can function in both kinetics and full frame modes, a moveable mask is required. To minimize the effective distance between the intensifier photocathode and this mask, a fiber optic window is used on the input of the intensifier. Precision screws adjust the mask from no coverage for standard spectroscopy to nearly full coverage for kinetics mode. Finally, to meet the unique gating requirements of this detector, a built in high voltage pulser, Model FG-101 is provided standard.

Image intensified detection

CCD Array Thomson Model 7895, full frame CCD, front illuminated, MPP only, 512 â 512 pixels (1:1 aspect ratio), 19 â 19 µm pixels; For other arrays call the factory Intensifier 18 mm diameter with fiber optic input window Method of Coupling 1.2:1 fiber optic reducer Vignetting None, since coupling is fiber optic Field of View 12 â 12 mm (16.9 mm diagonal) Sensitivity Up to 80 counts/photoelectron (adjustable from 1-80) Gating Speed 5 nsec FWHM for fast gate, 50 nsec FWHM for slow gate but with higher QE Pulser Model FG-101 Pulser is built in, see page 61 for detailed specifications of this pulser

CCD Cooling Thermoelectric, down to -35°C with tap water, down to -45°C with 0°C coolant Photocathode Cooling About 12° centigrade below ambient by nitrogen flow CCD Read Noise < 1.3 counts RMS at 100 kHz; < 2 counts RMS at 1 MHz; both numbers assume 15 electrons/count A/D calibration Spectroscopic Dynamic Range 16 bits at 100 kHz; 14 bits at 1 MHz High Voltage Supply Integrated into the detector head Configurations Available M, AIMO (MPP) CCD option; G, fast-gating; S, slow gating; RB, red-blue UV-NIR photocathode Spectral Range 380-800 nm due to fiber optic input; 180-800 nm with UV-to-visible converter

Aperture Adjustment From 0 to full CCD; adjustment and alignment via precision screws Mask Penumbra Approximately 2 pixels in an f/4 system Mask Edge Straightness Within 3 µm Vertical Shift Rate 1.5 µsec per row Linearity Depends on MCP photocurrent density; use of frame accumulation in hardware will extend the linear dynamic range; Linearity of an ICCD detector is a complex interplay of variables, including the phosphor decay time, the nature of the experiment timing, and the peak current density in the MCP relative to the MCP standing current. As a rule of thumb, pulsed experiments with time spans shorter than 1 msec become nonlinear above approximately 1,000 counts per pixel per frame.

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PG-200 Programmable Gate Pulse Generator

Image Intensified detectors

The Model PG-200 Gate Pulse Generator is the most powerful gate pulse generator from Princeton Instruments, allowing gating pulses from 3.5 nsec to 80 msec and allowing full computer control of all gating parameters. This pulser can control any Princeton Instruments ICCD detector, both fiber coupled and lens coupled models. The Gate Pulse Magnitude -200 V typical Pulse Repitition Rate 10 kHz maximum Pulse Width 3.5 nsec to 80 msec, adjustable in 1 nsec increments (2 nsec increments up to 15 nsec) Pulse Delay Control The interval between and the output pulse delay) is continuously 25 nsec to 80 msec, in the trigger pulse (propagation adjustable from 1 nsec increments

PG-200 has the maximum range of gate pulse widths available, the allowable pulse widths for any system being a function of both the pulser and the intensifier purchased. Low propagation delays minimize light loss and increase the number of possible experimental setups. The PG-200 uses microprocessor control to set all gating and delay param+10 V either by potentiometer or digitally. Either positive or negative pulses can be used. AC/DC coupling is offered, at 50 or 2 k Optical Trigger Direct optical triggering via a built-in photosensor, second pulser board Inhibit Inputs 2 inhibit inputs allow external override of the pulser using positive or negative logic signals Pulse Monitor A low level output (approximately -2 V) to measure the timing characteristics of the gate pulse Delayed Trigger Outputs 2 variable pre/post-gate delayed pulse outputs for precisely synchronized triggering of other devices Front Panel Dedicated function keys provided for gate pulse delay/width, delayed trigger output, input trigger level monitor, and input trigger mode selection. Additional keys available for features such as gate pulse delay "box-car" sweep, internal trigger frequency set, panel dim, parameter review, initialize, etc.

eters. This microprocessor allows precise, repeatable numerical setting of pulse and delay values. These values are displayed on a digital readout, which is factory calibrated for each individual pulser. These parameters can be programmed directly through the serial port of the computer for complete experiment automation. Temperature Control Temperature-compensated automatic self-calibration Memory Battery backed-up memory saves settings and instrument calibration constants Serial Interface RS-232-C; 1 start bit, 8 data bits; 1 stop bit, no parity, 9600 baud MCP-100 Option Provides high voltage required of Princeton Instruments image intensifiers. See the detector data sheets for models that require this option. Intensifier bias levels of several thousand volts are provided via a special high voltage connector with a safety interlock.

Pulse Jitter Less than 0.5 nsec or 0.05%, whichever is greater Repetition Rate Generator Internal trigger pulse generator is continuously variable from approx. 2 Hz to 10 kHz dependent on delay and width. It produces a trigger for synchronized triggering of another device, such as a laser External Triggering The PG-200 includes a sensitive trigger detector of low level trigger pulses from an external source. Trigger sensitivity is variable from -10 to

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FG-100 Gate Pulse Generator

Image intensified detection

The Model FG-100 Gate Pulse Generator is designed to provide medium to fast gate pulses, allowing gating pulses from 3.5 nsec to 2.5 µsec. An option for this pulser allows pulses as short as 2 nsec.

This pulser can control any Princeton Instruments ICCD detector, both fiber coupled and lens coupled models. The FG-100 can provide medium to fast gate pulses, the allowable pulse widths for

any system being a function of both the pulser and the intensifier purchased. Low propagation delays minimize light loss and increase the number of possible experimental setups.

Gate Pulse Magnitude -200 V typical Pulse Repitition Rate 5 kHz maximum Pulse Width Gate pulse output has 50 termination; Fixed Width Pulse: Pulse width is determined by the internal delay line selected; 3.5 nsec FWHM typical, 2.5 nsec rise time typical, 2.6 nsec fall time typical; Variable Width Pulse: Pulse width is continuously adjustable with a 10-turn potentiometer used in conjunction with a 2-position range switch; Range 1; 18 to 400 nsec (rise time 8-9 nsec) typical; Range 2; 35 to 2500 nsec typical Fast Pulse Option A fast pulse option available for the FG-100 allows pulses of 2 nsec FWHM optical gate width. Note that the gate voltage at these speeds is reduced relative to the standard FG-100, leading to some degradation in resolution and gain. FG-100 jitter and repetition rate dependency are also not negligible for these gating speeds.

Pulse Delay Control The time interval between the trigger pulse and the output pulse (propagation delay) is continuously adjustable from below 25 nsec to above 1700 nsec. With the variable width pulse, the minimum propagation time is approximately 30 nsec. A 10-turn potentiometer/3-range switch arrangement provides delays of 20-53, 50-270, and 80-1700 nsec Pulse Jitter Less than 1 nsec Repetition Rate Generator Internal trigger pulse generator is continuously variable, with 10-turn potentiometer, from approximately 30 Hz to 2 kHz. It produces pairs of trigger pulses allowing a precise synchronized triggering of another device; e.g., laser. Two connectors are available for these pairs. The two trigger pulses are delayed relative to one another in a variable range of 7-70 microseconds. This range can be varied according to user's requirements External Triggering The FG-100 includes a sensitive trigger

detector for the detection of low level trigger pulses from an external source. Trigger sensitivity level is variable from approximately 0.1 to 2.0 V (although higher level trigger pulses can be used). Either positive or negative, AC/DC trigger pulses can be used, at a rate of up to 5 kHz. Direct photosensor triggering is optional. Inhibit Inputs Two digital lines allow external pulser control using either TTL low or TTL high signals Pulse Monitor A low level output used to monitor the timing characterisitics of the variable gate pulse Delayed Trigger Output 1 fixed delay post-gate pulse output for triggering of another device MCP-100 Option Provides high volatge required of Princeton Instruments image intensifiers. See the detector data sheets for models that require this option. Intesifier bias levels of several thousand volts are provided via a high voltage connector with a safety interlock.

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PG-10 Gate Pulse Generator

Image Intensified detectors

The Model PG-10 Gate Pulse Generator is designed to provide slow to medium gate pulses, allowing gating pulses from 200 nsec to 5 msec. It is also the most economical gate pulse Gate Pulse Magnitude -200 V typical into a 1 M load Pulse Repetition Rate 4 kHz maximum at the minimum pulse width Pulse Width Varies over 5 ranges. Typical: Range A, 180 nsec - 1.8 µsec; Range B, 1.2 µsec - 12 µsec; Range C, 8 µsec - 80 µsec; Range D, 70 µsec - 700 µsec; Range E, 600 µsec - 6 msec. Typical pulse characteristics: rise time, 40 nsec; fall time, 25 nsec

generator from Princeton Instruments. This pulser can control any Princeton Instruments ICCD detector, both fiber coupled and lens coupled models. The PG-10 can provide slow to mePulse Varies Range Range Range Range Range Delay Control over 5 ranges. Typical: A, 270 nsec - 1.5 µsec; B, 1.0 µsec - 10 µ sec; C, 8 µsec - 80 µsec; D, 70 µsec - 700 µsec; E, 650 µsec - 7 msec

dium gate pulses, the allowable pulse widths for any system being a function of both the pulser and the intensifier purchased.

lnhibit Inputs Two digital (BNC) lines allow disabling of the PG-10 Pulser via TTL low or high level signals Pulse Monitor A low level output that represents the timing characteristics of the gate pulse MCP-100 Option Provides high voltage required of Princeton Instruments image intensifiers. See the detector data sheet for models that require this option. Intensifier bias levels of several thousand volts are provided via a special high voltage connector with a safety interlock.

External Triggering Input: 0.6 to 5 V trigger pulse controlled by a level potentiometer. Slope: Selects positive or negative trigger input; Coupling: Selects AC or DC coupling of the trigger input Delayed Trigger Out A TTL low pulse output 5 µsec wide approximately 45 µsec after the falling edge of the gate pulse

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FG-101 Built-In Gate Pulse Generator

Image intensified detection

The Model FG-101 Gate Pulse Generator is completely housed within the ICCD detector head. This compact design nevertheless offers gating pulses from 5 nsec to DC. The Model FG-101 is available in most Princeton Instruments fiber coupled ICCD models. It has a wide range of gate pulse widths, the allowable pulse

widths for any system being a function of both the pulser and the intensifier purchased. The FG-101 has two possible modes of operation. In the first, TTL pulses from any source are input on the back of the detector. Although pulse widths are longer, this mode offers a standard way of gating for many applications. The

second mode of operation requires a delay generator such as the Model DG-535 from Stanford Research. This mode allows the full range of gate pulses, as indicated below. Factory retrofitting of the FG-101 may be available; contact your sales representative for details.

Gate Pulse Magnitude 220 V peak-to-peak Pulse Repetition Rate 5 kHz maximum Pulse Width 5-7 nsec in Start/Stop mode, 5 nsec rise time, 6 nsec fall time; 50 nsec in TTL Gate mode; longest pulse width is DC

Pulse Delay Propagation delay is 8 nsec in Start/Stop mode, 18 nsec in TTL Gate mode; Note that this is only the delay of the FG-101. If it is used with the Stanford Research DG-535, its delay should be considered as well. Pulse Jitter Less than 1 nsec in Start/Stop mode; Less than 2 nsec in TTL Gate mode

Start/Stop Mode Input 5 to 0 V falling edge, 50 , compatible with DG-535 from Stanford Research TTL Gate Input 5 V maximum input, 10k/20 pF impedance Models Supported The FG-101 is currently available on the ICCD-576, ICCD-576LD, ICCD-512 Kinetics

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IIC-100 Image Intensifier Power Supply

Image Intensified detectors

The IIC-100 supplies high DC voltage for Princeton Instruments lens coupled and other intensified detectors where the high voltage is not already built-in. It is a stand-alone version of the MCP-100 option available for all Princeton Instruments Gate Pulsers. Individual detector data sheets indicate whether or not this power supply is required. The IIC-100 is available for Gen II or Gen IV intensifiers, however, the type of intensifier must be specified at the time of order. The IIC-100 allows the user to vary the MCP voltage, thereby varying the inten-

sifier gain. The phosphor voltage remains fixed, retaining the same intensifier resolution even at low intensifier gain settings. For applications where the average light level varies significantly, the automatic brightness control option adjusts the MCP voltage inversely to the signal, reducing MCP gain at higher light levels. This feature greatly facilitates focusing while the light level is changing. An alarm feature automatically shuts down intensifier operation in case of excessive exposure to light.

The IIC-100 only provides DC voltages to the image intensifier. By itself it can bias the intensifier on and off in less than 100 microseconds. Experiments requiring shorter gate widths also require a Princeton Instruments pulser. A pulse of approximately 200 V from the pulser is used to turn the intensifier on and off in as little as a few nanoseconds. A built-in version of the IIC-100, called the MCP-100 option, is available for all Princeton Instruments pulsers.

MCP Power Supply 500 to 1,000 V, 50 mA maximum Intensifier Bias Levels Phosphor, 0 V; MCP out -4,000 to -5,500 V; MCP in -5,000 to -6,400 V; voltages are set for Gen II or Gen IV operation at the factory Photocathode to MCP-In Gen II, -180 V in CW mode, +60 V in gate mode; Gen IV, -900 V in CW mode, +60 V in gate mode

Input Gate Pulse -200 to -900 V depending on intensifier; 5 nsec to 1 msec; gate pulse must be provided by a Princeton Instruments pulser Shutter Pulse 5 V logic, 0 V turn off, 50 µsec minimum exposure when operated by PI controllers Automatic Brightness Control Gain reduction of 16 typical under maximum incident light

Over-Current Shutdown 30 nA typical; Over-current condition sounds audio beeper Minimum Shutdown Period 3 seconds Audio Beeper Sounds alarm if intensifier is exposed to excessive light levels

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CPC-100 Photocathode Cooler
The Princeton Instruments CPC-100 Photocathode Cooler is a option for some Princeton Instruments intensified detectors that allows cooling of the image intensifier. This substantially improves performance for exposures of several seconds or more, where the noise of the image intensifier becomes a significant factor. An image intensifier is composed of a photocathode, a microchannel plate (MCP), and a phosphor screen. The dominant source of noise in these intensifiers is the shot noise associated with thermally generated photoelectrons emitted from the surface of the photocathode. It is referred to in the industry as EBI: Equivalent Brightness Illumination. Redenhanced intensifiers have higher than average EBI, due to their different makeup. Reduction of EBI for an intensifier is accomplished by cooling it. The CPC-100 uses liquid coolant from a closed cycle refrigerator to directly cool the image intensifier and the photocathode. This method is superior to gas cooling, which can sometimes allow ice microcrystals to form, damaging to the intensifier. The CPC-100 provides very efficient photocathode cooling, 12°C above the temperature of the circulating coolant. Relatively small coolers, such as the Neslab model RTE-110, provide adequately low temperatures for this

Image intensified detection

application. As an example, with -26°C methanol coolant and a CCD temperature of -20°C, EBI is reduced by at least a factor of 5. To better understand the significance of photocathode cooling, consider an experiment requiring an exposure of several seconds. This requires that SEBI << Sph, where Sph is the measured signal and SEBI is the EBI signal. A reduction in EBI therefore results in a proportional reduction in the minimum detectable signal

and in a square-root increase in the S/N performance (assuming EBI is dominant noise factor). Finally, to succeed in measuring these low signals it is essential that both the CCD and the photocathode be precisely thermostated to ±0.1°C for accurate background subtraction. Many ICCD detectors previously purchased from Princeton Instruments, Inc. can be modified for operation with the CPC-100 Photocathode Cooler. Please contact the factory for details.

Photocathode Cooler Direct contact intensifier cooler assembly, thermally insulated from the detector housing; achieves about 12°C above the temperature of the coolant CCD Cooler Thermoelectric and regulated, identical to that used in the standard ICCD model CCD Thermostating ±0.040°C

Photocathode Thermostating ±0.01-0.05°C, depending on selected refrigerator Typical EBI At -26°C using methanol; 0.2-0.5 counts/pixel-second for blue intensifiers, 0.5-1.0 for red/blue intensifiers, or 1-3 for red enhanced intensifiers

Coolant Connections Thermally insulated coolant tubes are provided, ready for attachment to the refrigerator Models Supported The CPC-100 is as of this writing available on the ICCD-576E and the ICCD-576LD-E detectors

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