DetectorsSingle Photon Counting ModuleDescriptionOur count series of Single Photon Counting Modules has been developed to offer a unique combination of high quantum efficiency, wide dynamic range and ease of use for photon counting applications. Combining LASER COMPO- NENTS ultra-lownoise VLoK silicon avalanche photodiode with specially developed quenching and signal processing electronics from PicoQuant GmbH, the module offers everything needed for single photon detection from 400 1000 nm. Incoming photons generate corresponding electrical pulses which may be conveniently read out at the TTL output. The gating function allows the module to be disabled between measurements to provide protection against accidental overload. The optional FC connector provides a convenient method for connecting the module to the sample using a multimode optical fiber. As an additional option, modules optimised for timing resolution are also offered (data sheet is available upon request).FeaturesExtremely low dark count ratesDetection efficiency 70%Optional FC fiber connectorSingle 12 V DC supply operation Stable count rate (no bi-stability)ApplicationsConfocal microscopyParticle sizingFluorescence analysisLIDARAstronomys a l e s o p t e .co m .cns a l e s o p t e .co m .cnDetectorsSingle Photon Counting ModuleTechnical Specifications for COUNT ModuleParameterMin.Typ.Max.UnitSpectral range4001000nmDark count rate COUNT-20C COUNT-50C COUNT-100C COUNT-250C20 50 100 250Counts/s Counts/s Counts/s Counts/sPhoton detection efficiency Pd1 at: 405 nm 670 nm 810 nm5 60 4015 70 50% % %Pd variation at constant temperatureTBC%Active area diameter (nominal) 2100mTiming resolution 3800psAfterpulsing probability 40.51%Dead time4755nsGating input voltage Gating on (= disable module) Gating off (= enable module)TTL low (2.4)V VGating input response time Gating on (= disable module) Gating off (= enable module)20 8540 100ns nsTTL output pulse length25nsTTL output pulse amplitude (into 50 Ohm)3VDelay between photon impact and TTL pulse50nsSupply voltage11.512.012.5VSupply current (switch on)1.5ASupply current (operation at 1 Mcps)0.2A1 Specifications valid for modules without FC-connector2 The active area of the integrated Si-APD is larger than 100 m. The FC-version is optimised for optical fibers with core diameter 105 m. The pre-aligned GRIN lens focuses the light onto a spot of 70 m diameter in the centre of the detector. Please also see Fig. 2 and 3.3 Timing resolution depends on count rate and wavelength. Modules specifically optimised for timing resolution are also available4 Defined for a time interval of 4 ss a l e s o p t e .co m .cns a l e s o p t e .co m .cnDetectorsSingle Photon Counting ModuleAbsolute Maximum RatingsMin.Typ.Max.UnitSupply voltage11.512.012.5VOperating temperature1040CStorage temperature-2070CCount rate5MCounts/sFiber Connection OptionThe COUNT-XX-FC has a FC-style fiber-optic receptacle pre-aligned to the optical detector surface. The standard GRIN lens used in this assembly is optimized and AR-coated for the range 400 700 nm. Please contact LASER COMPONENTS or its authorised distributor if your application requires optimisation for a longer wavelength. Optical Fiber ShieldingTo avoid stray light impinging on the detector and affecting the count rate, any optical fiber assembly attached to the FC connector must be completely opaque. LASER COMPONENTS offers suitably shielded optical fiber assemblies, please contact us for details. Gating FunctionThe COUNT module features a gating input provided as standard. This can be used for viewing a signal that occurs only in a small timeframe window, or in applications with very weak signals and higher background. The output of the module is disabled when a TTL low level is applied to the gate input. Applying a TTL high level will ena- ble the module and permit photon detection. If the gate input is left unconnected, the module is enabled by default.SaturationThe photon count rate rolls off at high incoming light levels. The count rate at which the output starts to decrease is called the saturation point. The control electronics feature a built-in current limiter designed to prevent damage to the APD when exposed to high light levels. Precautions should however be taken to avoid prolonged exposure excessive light levels that may damage the COUNT module.s a l e s o p t e .co m .cns a l e s o p t e .co m .cnDetectors4Single Photon Counting ModuleWarrantyA standard 12-month warranty following shipment applies. Any warranty is null and void if the module case has been opened. Warranty is void if the module input exceeds 12.5 V.ESD InformationModules should only be handled at an ESD-safe work station.Individual Module Test DataEach module is supplied with test data indicating the modules actual dark count, dead time, photon detection efficiency 405 nm, 670 nm and 810 nm and afterpulsing pr