InGaAs - Micro Photon Devices
Contents
1. Single Photon Detection Module freerunning USER MANUAL VERSION 4 0 2 SEPTEMBER 2014 Micro Photon Devices S r l Italy All Rights Reserved MICRO PHOTON DEVICES InGaAs Single Photon Detection Module Free Running version O Micro Photon Devices S rl GmbH Via Stradivari Ae Stradivari Strasse 4 39100 Bolzano Bozen BZ e Italy Phone 39 0471 051212 e Fax 39 0471 501524 Table of Contents GORING SIAM e ME T ET Tol Tu deel Lee EE 1 1 2 The photon detection module u22002402002000200 000 nen nnn ann nnn nennen 2 1 3 The Control Units Front Panel 4 1 4 The Control Unit s Rear Panel S 1 5 The InGaAs InP Single Photon Avalanche Diode 6 120 BIDLOQL DN VE 8 Z JEE 2 1 Software Installation and Startup 9 EVI u CRM 10 2 3 UIN P uuu u 22 12 24 Module E e EE 15 25 The Summan eebe 22 3 Using the INGGAS ee EI 3 1 Powering on off and operating the InGaAs module 23 5 2 E e Te E 26 3 3 TrOUDIGSIOOLHILIO E 29 or aree UE 35 A SDEEINCALUONS unsern era M epebSu Rao AEGEE 4 1 Instrument Input fngogeriN 36 4 2 Instrument LVTTL Outputs Trigger Out Valid Gate 36 4 3 In2. gilt ULV InGaAs InP H Single Photon Detection Module Z Control Unit B micno PROTON ann SS w lt TE IN E e oer P jon MOD inGaAsin petectio photon singe n Head Detect CONTROL UNIT DETECTION HEAD Figure 1 1 A standard configuration for the InGaAs InP single photon detection module 1 2 2 Preparation for use and care Before using and powering on the module the following precautions must be followed 1 The InGaAs Single Photon Detection Module MUST be unpacked and set up as reported in paragraph 3 1 1 Micro Photon Devices S r l Italy All Rights Reserved 2 GETTING STARTED NEVER switch off the module if the SPAD has not being turned off by the control software as explained in paragraph 3 1 4 Avoid switching on the module if the orange wide bandwidth cable has not been properly connected to both the Control Unit and the Detection Head Never un connect the orange wide bandwidth cable if the module is powered on In order to use the module the controller software has to be installed on a PC following the instructions in paragraph 2 1 Before connecting any cable to the front panel connectors make sure that signals are compatible with the levels specified in Chapter 4 Also pay attention on signals polarity and invert them if necessary 1 2 3 Care of the SPAD optical interfaces Please follow these instructions for fiber care 1 ot ly avoid any unne
3. Configurations buttons 2 4 4 Manage Module Configurations The InGaAs Single Photon Detection Module automatically saves and recall at startup the last settings used but sometimes it is more convenient to save different configurations for different setups For this purpose you can use the Save to File or the Load from File buttons shown in all the module tab pictures and highlighted in Figure 2 14 If one of these buttons is pressed a standard save or load window appears and it is possible to create overwrite or open an existing file in the preferred directory All user data including the SPAD settings are stored in a single binary file any time the Save to File button is pressed In order to force the software to recall and display the parameters currently set on the module the Load from module button can be used All previous unsaved data will be lost Note At module startup the last parameters that have been successfully uploaded in the module are automatically reloaded shown and highlighted in blue without the need of pressing the Load from module button 2 4 5 Error control In case of errors the module tab will be framed in a red rectangle as shown in Figure 2 15 The module tab name will also turn red A red LED in the Module Status Overview will mark the error type Please refer to paragraphs 2 4 3 and 3 3 for a correct understanding of the various possible errors and for troubleshooting In case of a communication e
4. THE INGAAS MODULE 3 1 4 otherwise the SPAD might be permanently damaged If during the standalone functioning some errors occur they will be reported after the device detection procedure Note When the USB cable is detached form the module with a biased detector a Communication Error occurs this errors signals that the module is still operating and that it has to be to reconnected later to the PC in order to turn the SPAD off correctly 3 2 Basic Setups In this section simple test measurements are outlined and briefly explained 3 2 1 Photon Counting setup Photon counting is the simplest measurements performable with the module and Figure 3 1 shows a possible example of an experimental setup It consists of a continuous wave laser that produces photons at 980 nm properly attenuated and a sample that absorbs photons and re emits in the near infrared range These photons properly collected are sent to the SPAD detector inside the Detection Head The module does not need any particular configuration since it works in free running mode its photon out output is simply connected to a counter that counts the number of photons per seconds i e counts per seconds cps The only thing to remember it that due to the long hold off time Tuo the photon count rate differs from the module count rate InGaAs InP Single Photon Detection Module PHOTON VALID TRIGGER TRIGGER DUT GATE OUT IN MICRO PROTON DEVICES Counter INPUT
5. VL S ul peurejdxe se UJ9 s S oU JOOUUODSY ON NO pesemod si Jojo8jep Vds e npoui au oj 9 qe ASN eui u ejes ON amp 9 qe y poejoeuuoosip Ajjeuonue no e eH SoA ON 40413 GVdS sodas pue qd led punoJ6 1ejs owes y UO un OJJUOO pue Id 199uuoo J011J uoNesiunwWwon e syoda pue AAN Ieo SOA sdoo punos6 SWOS 1 u UY ON Sal LOA SI eiqe gSN lqe5 gsn 6ueuo S9A p l o uuoo SI eiqe ISN oDed xau uo enuguoo Q3 S uoyng snjejs v FlowChart 1 30 All Rights Reserved Micro Photon Devices S r l Italy USING THE INGAAS MODULE continue from previous page System Ready TOR is warm when the error bed Y Yes NO System Ready Disconnect and reconnect the orange cable between Control DE U Unit and Detection Head taking care on routing see 83 1 1 Dissipate heat in a better way such as connecting Head to a large surface Call MPD and reports a Temperature Error Call MPD and reports a System Error Reconnect the system as explained in 83 1 2 Micro Photon Devices S r l Italy All Rights Reserved 31 USING THE INGAAS MODULE Control Unit fan is not rotating Power down the module Remove the fuse inlet No Change fuses with ones Fuses are good with same characteristics as reported in 84 8 Change th
6. VOA EA Figure 3 1 Simple setup for a photon counting measure green optical signals pink electric signals Micro Photon Devices S r l Italy All Rights Reserved 26 USING THE INGAAS MODULE As explained in paragraph 1 5 see it for details the photon count rate CRphoton can be calculated from the module s count rate CR with the following formula CR n D 3 2 2 Photon Timing setup Another typical setup in which the InGaAs Single Photon Detection Module is used is a photon timing one illustrated in Figure 3 2 This setup can be adopted for the measurement of fast waveforms of repetitive optical pulses The technique is commonly known as Time Correlated Single Photon Timing TCSPC and is extensively described in ref 1 and 2 This setup consists of a pulsed laser source which excites a fluorescent sample that reemits photons with an exponential decay In this example the laser is the source of the synchronization signal its trigger out signal is then as START of a TCSPC system The STOP signal to the TCSPC system is given by the photon out of the Control Unit the STOP marks the arrival time of the detected photon at the diode For example in case of using a PicoQuant PicoHarp 300 3 the laser sync is usually connected the Channel 0 input and the photon out is normally connected to the Channel 1 input If the B amp H SPC 130 4 or similar cards are employed instead please read carefully their manual because these ca
7. be shown Free running Mode User Manual when pressed the default PDF reader will be opened and the InGaAs user manual for the free running mode module version will be shown Check Updates automatically when this item is ticked on start up the InGaAs control software will look for software or user manual updates on the MPD website o Incase a new user manual is present the dialogue box shown in Figure 2 6 on the right will appear and if the user presses the Yes button the new user manual is downloaded and copied inside the program A dialogue box signaling the successful install of the new manual will also be shown as illustrated in Figure 2 7 o Incasea new software is available the dialogue box shown in Figure 2 6 on the left will appear If the Yes button is pressed the default web browser will be opened directly on the download page of the MPD website DEVICES Version 5 3 0 11 Figure 2 7 Dialogue box informing that the Gated Mode User Manual has been downloaded Micro Photon Devices S r l Italy All Rights Reserved 14 THE CONTROL SOFTWARE InGaAs InP Single Photon Detection Module L m File Settings Help Cc MPD InGaAs InP Single Photon Detection Module DETECTION MODULE CONTROL MODULE STATUS OVERVIEW Di Apply Settings Q and Turn On SPAD Update Configuration CU SN 00029 DH SN 00048 GATE SETTINGS SPAD Temp This detection head works in free running mode TC
8. different applications The system is composed by two parts A Detection Head which comprises of a InGaAs InP SPAD detector and the related fast electronics Its small dimension allows its easy integration in all experimental setups The detection head can be of two types Gated mode or Free running A Control Unit which contains the pulse generator the Peltier controller the communication system and the power supplies of the entire module The control unit is the same for both types of detection heads They are connected together through a 2 m long wide bandwidth cable The system can be conveniently used both for counting and timing measurements since the high performance electronics guarantees a clean temporal response even with fast gate transitions Micro Photon Devices S r l Italy All Rights Reserved 4 GETTING STARTED 1 2 The photon detection module 1 2 1 Standard module configuration A standard InGaAs Single Photon Detection Module is usually shipped with these parts e Control Unit Detection Head either with a fiber pigtailed SPAD or with the detector placed behind a standard glass optical window Orange wide bandwidth Cable for Control Unit to Detection Head connection MPD universal optical table adaptor for Detection Head mounting optional e Power cord USB key containing the installation software and the user manual in PDF format ASPAD test report WIDEBAND CABLE
9. e By expressing Nimp as a function of Neounted and dividing both sides by T one obtains N N counted imp r N eq 2 js GINA a X Tus This means that the actual photon counting rate can be calculated simply by dividing the measured counting rate divided by 1 minus the measured counting rate multiplied by the hold off Normally instead of the hold off the dead time should be more correctly used since the dead time is the sum of the hold off plus the time needed to quench and reset the SPAD 1 Anyway in case of InGaAs diodes the hold off is so long compared to the quench and reset phased that they practically coincide Please note that the previous equations do not take into account the Photon Detection Efficiency of the InGaAs module These formulas also strictly apply when the photon rate is uniformly distributed over time Micro Photon Devices S r l Italy All Rights Reserved 7 GETTING STARTED Bibliography SPADs and quenching circuits Cova S Ghioni M Lacaita A L Samori C and Zappa F Avalanche photodiodes and quenching circuits for single photon detection Applied Optics 35 12 1956 1976 1996 http dx doi org 10 1364 AO 35 001956 Cova S Ghioni M Zappa F Rech I and Gulinatti A A view on progress of silicon single photon avalanche diodes and quenching circuits Proceedings of SPIE 6372 pp 637201 1 637201 12 2006 http dx doi org 10 1117 12 685963 InGaAs InP SPAD
10. or equivalent processor 500Mb or 1 GB of RAM 1 GB of free disk space 1024 x 768 pixel display resolution USB 1 1 or 2 0 port Minimum recommended system requirements Micro Photon Devices S r l Italy All Rights Reserved 40 SPECIFICATIONS 5 Changelog 401 first MPD official release 40 2 updated gated off time characteristics expanded error section changelog is now included inside this manual Micro Photon Devices S r l Italy All Rights Reserved 41
11. populates the tabs with one page for each recognized system Tabs report the Custom Name that has been given to each module Micro Photon Devices S r l Italy All Rights Reserved 11 THE CONTROL SOFTWARE COM ports Interface aspect 9 Multiple modules J Single module COM selection Search COM Automaticall y Static CON n number COM exclusion List Figure 2 3 COM ports configuration window 2 3 Menu bar The menu bar has three menus File Settings and Help The File menu has only one item Exit and is used to exit immediately the program when the SPAD is turned off By pressing the Settings menu two items are shown COM ports and Advanced By pressing the first item of the list a configuration window shown in Figure 2 3 will appear Inside this window there are the following controls Interface aspect radio button it lets you to switch between multiple or single module interface Using this last option tabs are not shown and only one module can be managed This option is very useful when only one photon counter has been attached to a single PC Search COM automatically checkbox in Multiple modules interface mode always enabled This option can be set as desired only if the software has been set in Single module interface mode If disabled it does not force the program during the start up to find automatically the right COM port where a module is connected This option is very useful when the PC handle
12. the afterpulsing effect is much higher and the time constants have values in the range of Micro Photon Devices S r l Italy All Rights Reserved 6 GETTING STARTED microseconds As a consequence it is necessary to use hold off in the order of few or few tens of microseconds Now due to the hold off time the SPAD has a linear working range which means that the number of detection events within a defined time period T depends linearly on the illumination intensity only for photon fluxes much smaller than the reciprocal of the hold off time At large photon fluxes the number of detected photons deviates from linearity and saturates to a constant value which is the reciprocal of the dead time Tuo When the deviation from linearity is moderate counting rates smaller than 1 2Ty it is possible to evaluate the deviation from linearity and to correct the measured counting rates as described here below Supposing the Photon Detection Efficiency 100 for simplicity Nimp the number of impinging photons on a SPAD active area during an integration time T Tuo the hold off time and Neounted the photons counted by the detector Noeounted is equal to Nimp multiplied by the ratio of the actual integration time divided by the set integration time T since every time the counter is triggered it becomes blind for a time Tuo I N ted Tyo Tuo Neounted Nimp c GG Nimp 1 Noounted TT thus N Neounted eq 1 1 Nimp
13. the detector is off you can select a SPAD preset i e the operating temperature excess bias and hold off of the photodetector from the SPAD Preset drop box menu The only SPAD preset that allows to modify the SPAD settings is the Advanced preset as shown in Figure 2 10 Completed this task by pressing this button all the settings are sent to the module and the detector turns on Micro Photon Devices S r l Italy All Rights Reserved 15 THE CONTROL SOFTWARE J InGaAs InP Single Photon Detection Module mx File Settings Help X MPD InGaAs InP Single Photon Detection Module DETECTION MODULE CONTROL MODULE STATUS OVERVIEW Turn Off SPAD Update Configuration CU SN 00029 3 DH SN 00048 GATE SETTINGS SPAD Temp This detection head works in free running mode TEC Controller SPAD SETTINGS SPAD SPAD Preset Temperature Excess Bias Hold Off GATE 233 0K 5 0V 20us Better Timing M 233 0K Detection MANAGE MODULE CONFIGURATIONS 233 0K Es z Em CH Save to file wi Load from file gt Load from module ACTUAL CONFIGURATION last module settings Start SN00048 Summary Figure 2 9 Module tab screenshot after having turned on the SPAD with Better Timing preset Update Configuration button this button becomes active only when at least one SPAD parameter has been changed after having pressed the Apply Settings and Turn On SPAD button The only SPAD preset that allows to modify
14. 0 Hz 1 2 4 5 8kHz 10 20 40 50 80 KHz 100 200 400 500 800 KHz from 1 to 25 MHz 100 KHz steps over 25 MHz 1 MHz steps Cycle to cycle jitter peak peak 100 ps 4 5 Gate Window and Hold Off programmability Note Gate window is meaningless for a Free running detection head 1 5 ns 10 ns 40 ps steps te Width T EEN 10 ns 500 ns 2 ns steps 1 5 ns 10 ns 40 ps te Width A DNL een er re ze Gate rise fall time 20 80 700 ps typ 1500 ps max Hold Off Time 1 us 3 ms 24 ns steps Hold Off Time Accuracy 3 5 ns Excess Bias range Se Ee Gated mode i 2V 5V Free Running mode if Ton lt 10 ns Minimum Gate OFF time if 10 ns lt Ton lt 100 ns if Ton gt 100 ns Micro Photon Devices S r l Italy All Rights Reserved 37 SPECIFICATIONS 4 6 Signal Propagation Times In Figure 4 1 are reported the most important waveforms related to the InGaAs Single Photon Detection Module that help the user to understand correctly the various internal and external signal propagation delays In Table 4 1 are reported the delays between these signal in various operating conditions TRIGGER SIGNAL o in gated mode it is the signal designated to be the reference it could be the internal trigger or the external one supplied by the user Note that the delay varies according to the selected trigger source Anyway reported delays are related to the respective front panel measured signal i e TR
15. 1 5 if you want use them in the standalone mode 4 tis now possible to press the power switch located in the back panel of each module in order to physically switch off the module 5 Before powering on again a Detection Module please wait for at least 20 seconds If the power switch is pressed before the closing of the software a warning window will signal that there is a communication problem This warning can in this case only be ignored 3 1 5 Standalone module use use with extreme caution The InGaAs Single Photon Detection Module can also be operated without a PC constantly connected In fact when the module is properly configured and the detector is biased correctly it can be detached from the PC removing the USB cable while it still runs the module can work without the need of the PC connection This is particularly useful when long measurements have to be performed and other instruments do not require a supervisor PC However the customer must be extremely careful when this modality is used the status of the module cannot be monitored through the control software and since the detector is biased the module cannot be switched off through the power switch In order to sately power off the system the module must be reconnected to the PC detected with the procedure described in Chapter 3 1 2 and correctly turned off using the procedure described in Chapter Micro Photon Devices S r l Italy All Rights Reserved 25 USING
16. 10 THE CONTROL SOFTWARE InGaAs InP Single Photon Detection Module e amp File Settings Help e MPD InGaAs InP Single Photon Detection Module Detected Modules COM name Connected Module Custom name CON SN00048 on SN00029 alpha PT Auto Detect x f Accept Config Start alpha Summary Figure 2 2 Start Tab schreenshot after module renaming and Accept Config button pressed Each tab will allow the user the full control of the associated photon counter as will be shown in paragraph 2 4 This table is automatically populated at each software startup with actual connected modules unless the user has disabled the automatically search feature in the COM ports panel as will be explained in paragraph 2 3 If other modules are connected to the PC without first closing the program it is necessary to manually press the Auto Detect button as explained into the following section 2 2 2 Auto Detect button Pushing this button the software scans each COM port available on the system and sees if there is any attached module then the Detected Modules table is updated according to the current scan This function is automatically run when the program starts unless you assign a static COM number in the Settings gt COM Ports configuration window 2 2 3 Accept Config button By pressing this button the custom names that have been assigned to the connected modules are confirmed and the program
17. 43 0K 3 2V Detection Head MANAGE MODULE CONFIGURATIONS Kris ni CH Save to file jJ Load from file Load from module System Ready TEC Error 0 6 Figure 2 15 Screenshot of a Module tab when an error is detected g InGaAs InP Single Photon Detection Module B File Settings Help amp MPD er MICRO PHOTON DEVICES Single Photon Detection Module DETECTION MODULE CONTROL MODULE STATUS OVERVIEW Turn Off SPAD A Update Configuration CU SN 00017 DH SN 00036 SPAD Temp Turning off is taking longer time than expexted Please press the OK button to start a diagnostic TEC routine and wait for about 20 seconds Controller SPAD SPAD Preset l i GATE I Advanced 240 0K IUS Head MANAGE MODULE CONFIGURATIONS ee n System Save to file Load from file L Load from module Ready ml ACTUAL CONFIGURATION last module settings Start SN00036 Summary Figure 2 16 Screenshot of a Module tab when a longer than expected SPAD turning off time is detected 13 InGaAs InP Single Photon Detection Module 6 InGaAs InP Single Photon Detection Module Se File Settings Help File Settings Help x MPD InGaAs InP InGaAs InP x wien PROTON DEVICES Single Photon Detection Module Teens Single Photon Detection Module DETECTION MODULE CONTROL MODULE STATUS DETECTION MODULE CONTROL MODULE STATUS OVERVIEW OVERVIEW Turn Off SPAD Z Update Configur
18. Gate Width m 0 00 ns Current Temperature 242 5K 243 0K Status OK OK TEC ON ON SPAD Turning ON OFF ON GATE ON Start alpha beta Summary Figure 2 18 Summary tab showing two connected modules one with a free running detection head and one with a gated one Micro Photon Devices S r l Italy All Rights Reserved 22 USING THE INGAAS MODULE CI 3 Using the InGaAs Module In this chapter examples of measurements and configuration procedures of the InGaAs Single Photon Detection Module are presented 3 1 Powering on off and operating the InGaAs module The following paragraphs illustrate some simple measurements in order to become familiar with the correct use and operation of the MPD InGaAs Single Photon Detection Module 3 1 1 Preparation for use and powering on the module Once verified that all the items listed in paragraph 1 2 1 have been bought it is possible to start preparing the system using the following simple steps 1 Install the Detection Head in the optical setup the use of the MPD universal optical table adapter is highly recommended If the pigtailed version of the Detection Head has been bought the loose end of the module fiber can be now connected through the use of a barrel to the FC PC connector of the optical fiber coming from the experimental set up Before the connection please be sure to follow the care instruction listed in paragraph 1 2 3 Connect the Detection Head to the Co
19. IGGER OUT or TRIGGER IN o in free running mode this signal is disabled the SPAD is always on it is quenched only if an avalanche occurs and it is enabled immediately at the end of each hold off time GATE WINDOW o in gated mode it is the SPAD enable signal measured directly on the detector Note this signal cannot be directly measured by the user o in free running mode the Gate signal is off during the hold off time only otherwise it is on AVALANCHE SIGNAL it is the SPAD output signal asserted when a photon is absorbed by the device This is an internal signal that cannot be measured by user PHOTON OUT itis the front panel output which reveals a detected incoming photon VALID GATE o in gated mode it is the front panel output which reports which Gate windows are effectively applied to the SPAD and are not masked during the hold off time Normally Gate Frequency and VALID GATE are matched but during hold off time the Gate Frequency trigger signal is masked and this output remains into the low logic state see paragraph 1 5 of the gated mode user manual o in free running mode the Valid Gate signal outputs the effective SPAD status i e when it is ON or OFF due to the hold off Table 4 1 Sienal propagation times into different operating conditions External Trigger 35 7 ns 10 I 11 3 ns 10 14 3 ns 596 Internal Trigger 25 0 ns 10 Micro Photon Devices S r l Italy All Rig
20. PADs the DCR would be so high that the use of these detectors would be almost impossible As a consequence for further reducing these unwanted counts the InGaAs SPADs are operated in gated regime the detector is periodically enabled for a short time window called Gate of duration Toy Gate Width whereas it is usually held off at a bias slightly below the breakdown voltage However a secondary source of noise exists in SPADs the afterpulsing During the avalanche some carriers are captured by deep levels in the junction depletion layer and subsequently released with a statistically fluctuating delay Released carriers can retrigger the avalanche generating afterpulses correlated with a previous avalanche pulse which sum up with the DCR In order to mitigate these avalanche re triggerings after each avalanche during the subsequent gating occurrences the detector is kept off for a user programmable time named hold off time Tyo In this way the trapped carriers can be released without triggering further avalanches The hold off time is particularly useful when cooling the detector since the afterpulsing effect worsens at low temperatures because the decay times of the trapped carriers increase Despite the fact that usually InGaAs SPADs are operated in gated mode in case of particularly good devices it is possible to bias them also in free running mode as with Silicon SPADs The main difference is related to the fact that in case of InGaAs SPADs
21. ation CU SN 00017 Turn Off SPAD Update Configuration CU SN 00017 a SPD lle lt SN0003 InGaAs SPD Module lt SN00036 gt DHSN oe EEE MIN SUR DHSN 00036 SPAD Temp SPAD Temp x Tl Diagnostic routine completed Diagnostic routine succesfully completed TEC SPAD Detector is unbiased but the false alarm cannot be removed TEC SPAD Detector is unbiased You can now use the module Controller Se Please reboot the system Controller close the software ignore any warning sap vn power off the module sap oo restart again after 20 seconds GATE wasa SPAD Preset GATE Rm Advanced 240 0K 3 0V Detection Advanced Detection Head Head MANAGE MODULE CONFIGURATIONS Beete a MANAGE MODULE CONFIGURATIONS apes r nr n KI Save to file Leadfromfile Load from module wm LJ swetofile Lead from file S Load from module System w ACTUAL CONFIGURATION last module settings ACTUAL CONFIGURATION last module settings Start SN00036 Summary Start SN00036 Summary Figure 2 17 Screenshots of Module tabs showing the results of the internal diagnostic routine trigeered after a longer than expected SPAD turning off time Test s successful ending message is shown on the left while a false alarm detection is shown on the right Micro Photon Devices S r l Italy All Rights Reserved 24 THE CONTROL SOFTWARE 2 5 The Summary Tab The Summary tab see Figure 2 18 illustrates all parameters that have been set for each currentl
22. be connected to this input The external trigger signal can be positive or negative within the range from 2 V to 42 5 V and the internal comparator allows for a programmable threshold For a complete understanding of module input and outputs and their absolute maximum ratings please refer to Chapter 4 Micro Photon Devices S r l Italy All Rights Reserved 4 GETTING STARTED 1 4 The Control Unit s Rear Panel DETECTION HEAD 2 VOLTAGE FREQUENCY POWER MAX 100 240V 50 60Hz 1 USB Connector holds the USB type B cable for PC connection 2 Detection Head cable connector holds the wide bandwidth cable for Detection Head and Control Unit connection 3 Power Switch used to switch on and off the module 4 Fuse Holder contains the 1 A fuse to protect this appliance 5 Power Inlet hold the power cord to supply the unit 6 Fan opening permits the air to recirculate into the unit Note Be careful during the module power off sequence ALWAYS remember to turn off the detector using the control software as described in paragraph 2 4 1 before switching off the module using the Power Switch Incorrect shutdown procedure can irreparably damage the SPAD detector Micro Photon Devices S r l Italy All Rights Reserved GETTING STARTED 1 5 The InGaAs InP Single Photon Avalanche Diode The core of this module is a Single Photon Avalanche Diode SPAD housed into the Detection Head The detector has a 25 um diam
23. cessary force that may cause the fiber to bend sharply and break bare fiber should not support the weight of the connector cap end face when connector is not in use inspect the end face of the fiber for dust or imperfections with a fiber microscope clean any dirt from the end face with a lint free wipe Please follow these instructions for the cleaning the window optical interface of your detection head 1 Dust and other loose contaminants usually should be blown off before any other cleaning technique is employed A canister of inert dusting gas or a blower bulb is needed for this method Do not use your mouth to blow on the surface because it is likely that droplets of saliva will be deposited on the optical surface If blowing off the surface of the optic is not sufficient other cleaning methods and materials are acceptable When cleaning an optic always use clean wipes and optical grade solvents to prevent damage from contaminants Wipes should always be moist with an acceptable solvent and never used dry Acceptable wipes are pure cotton lens tissue Typical solvents employed during cleaning are distilled water and isopropyl alcohol Use all solvents with caution since most are poisonous flammable or both Read product data sheets and MSDS sheets carefully before using any solvents If repeated cleaning is required it is recommended the use of distilled water to be used more frequently than the cleaning fluid and to app
24. correct module inside the program when controlling two or more modules with one single program however the serial number of both Control Unit and Detection Head is also reported inside the Module Tabs When all the connected modules are reported into the table and named the Accept Config button has to be pressed Now the custom names are stored in the PC and a module tab for each connected module is created see Chapter 2 for a more detailed explanation 3 1 3 Device configuration and detector turn on Before turning on the SPAD s for each tab relative to a connected module or for the only visible window when in Single Module Mode these steps must be followed 1 Make sure that Detection Head LED Control Unit LED and System Ready LED are all green they must remain green during all the system functioning If not see the paragraph 2 4 3 and 33 for troubleshooting 2 Select a SPAD Preset using the menu shown in Figure 2 11 If the Advance Mode has been chosen enter the desired device temperature excess bias and hold off time Completed these operations the Apply Settings and Turn On SPAD button can be pressed In the next seconds some status LED will be turned on with the following sequence 1 The TEC Controller LED will become yellow and then green during the yellow phase the detector temperature indicated by SPAD Temp field will change from the current temperature the ambient temperature if the detector has been left off for a
25. e power cord of Control Unit Power up the module again Yes The fan is rotating Power down the module Disconnect the orange cable from the Detection Head Power up the module again No Problem solved The fan is rotating Yes Call MPD and reports Call MPD and reports a Control Unit a Detection Head malfunctioning malfunctioning FlowChart 2 Micro Photon Devices S r l Italy All Rights Reserved INGAAS MODULE USING THE Buiuonounjjeui uoreorunuuloo uo 999 ny ssal uonn 9 O ssa uoyn 99 O sso sdoo punou yoeuD jqe gsn eBueu L 28 ul suornonujsur AO O3 Od JO anno Jamod euJes BY oj poyoeye SI Jun 04 UO yun lonuoo pue 9d uaemjaq lqeo JSN y 1p uuoo 1 pue j2euuoosi amp peljejsui Dapauo ale SIBAUP GSN Das MOU SI a npow ul Pe S MOU SI a npow Saul Das MOU SI a npow Saul Das MOU SI a npow ul peAos uie qoJd uonng 12ejepoiny sseJd t u S ees Bunnoi uo age uono uuoo5 Buiye pe H uono l q pue pun p H uornoeje jonuon usamjaq ejqeo eBueJo u Io1nuoo oj nof sil au 199uuoo 1 pue JOOULODSIG abessaw y uie6e npoui y dn jamod e npow y uwop JSAO0d sr s lnpolN pejoeuuo ay ul Jeedde jou seop ajnpo FlowChart 3 33 All Rights Reserved Micro Photon Devices S r l Italy USING THE No signal at outputs No All sta
26. em Controller SPAD SETTINGS SPAD Preset Temperature Excess Bias Hold Off GATE m Best Timing gt 233 0K 6 0V Agus Detect on NEN Head MANAGE MODULE CONFIGURATIONS ages mees ni lH System n Save to file ed Load from file L Load from module Ready EN ACTUAL CONFIGURATION last module settings Start andrea Summary Figure 2 8 Module tab screenshot before turning on the SPAD 2 4 Module Tab After clicking the Accept Config button in the Start tab the software creates a module tab for each attached system The tab label reflects the Custom Name given at the specific module Every module tab opens an interface whereby all the configurable parameters of the detector can be set In Figure 2 8 it is reported a page screenshot taken before turning ON the SPAD The next paragraphs will describe all the controls buttons and indicators that can be found into this window divided by section 2 4 1 Detection Module Control In this section of the panel there are two buttons Apply Settings and Turn On SPAD and Update Configuration Figure 2 8 The first button changes to Turn Off the SPAD after the InGaAs InP SPAD has been turned on as shown in Figure 2 9 and will revert to the first name after the turning off of the SPAD The two buttons are used to upload the user defined parameters in the control unit and turn on and off the detector In particular Apply Settings and Turn On SPAD button if
27. eter active area and it is mounted on the top of a three stage Peltier cooler A SPAD is a p n junction biased well above the breakdown voltage VB that stays in a meta stable state with no current flowing At this bias the electric field is so high that a single charge carrier injected in the depletion layer can trigger a self sustaining avalanche 1 The current rises swiftly nanoseconds or sub nanosecond rise time to a macroscopic steady level in the milliAmpere range If the primary carrier is photo generated the leading edge of the avalanche pulse marks the photon arrival time The current continues to flow until the avalanche is quenched by lowering the bias voltage down to or below VB Then the bias voltage must be restored in order to detect another photon These operations are usually performed by a suitable circuit named Active Quenching Circuit AQC 2 The device primary source of internal noise consists in a random dark counting rate DCR arising from free carriers thermally generated These events compete with photons in triggering the detector and thus impair the signal to noise ratio 3 The Peltier cooler is therefore useful to lower the temperature of the detector in order to diminish this effect Normally single photon detectors are operated in the so called free running mode where the devices is enabled immediately after the quenching of each avalanche current Normally this is true for Silicon SPADs but for InGaAs S
28. forces the nearest allowed maximum or minimum value Unlike others preset when the Advanced is selected the SPAD parameters can be changed even when the detector is on and running Modifications are applied by pressing Update Configuration button This operation according to the modified parameters may require a SPAD turn off and a reactivation Anyway this is automatically done by the module 2 4 3 Module Status Overview In this panel shown for example in Figure 2 10 and depicted in Figure 2 13 there are seven status LEDs and four other indicators The meaning of LEDs colors are TEC Controller LED it turns yellow to indicate that the thermoelectric cooler has been powered on and the temperature is going to reach the desired steady state value When the device reaches the right value the LED becomes green It is off while the TEC is inactive It turns red if the desired temperature is not reached SPAD LED it turns yellow to indicate the transient of the SPAD bias voltage to the correct value just below breakdown and green to point out the steady state of this one When the bias is inactive this LED is off It turns red if the correct bias voltage cannot be reached Micro Photon Devices S r l Italy All Rights Reserved 18 THE CONTROL SOFTWARE GATE LED it turns on with a green color when the SPAD is biased above breakdown on the contrary it is inactive when the SPAD is biased below breakdown This is true independen
29. hts Reserved 38 SPECIFICATIONS Trigger Signal Gate Window Avalanche signal PX Photon Out t OV 2 t 3 Figure 4 1 Signals waveform with delay times highlighted 4 7 Detector 1550 nm Vex 2 5 V 1576 typ Free space 228 K 290 K Gated mode 228 K 243 K Free running mode Max DCR Grade A lt 40 kc s GradeB lt 20k SPAD performances T 233 K Vex 2 5 V rs diae e Typ FWHM eV V The distance from the top of the cap to the active area is 2 9 mm and the glass window is recessed approximately 0 75 mm Optical Interface free space so the distance from the detector surface to the outside surface of the glass window is about 2 15 mm Optical Interface pigtail single mode SMF 28 fiber with FC PC connector Detector minimum temperature may depend both on operating environment temperature and Detection Head case power dissipation Please improve thermal conduction if a TEC Error occurs With not focalized beam Can be lowered if light is focalized on a small area Micro Photon Devices S r l Italy All Rights Reserved 39 SPECIFICATIONS 4 8 General Specifications Control Unit Dimensions Detection Head Dimensions Weigh Continuous Power Requirements Operating Environment Storage Environment 4 9 System Requirements for Software 8 7 Vista both 32 and 64 bit XP Server 2003 R2 only 32 bit Server 2008 R2 only 64 bit Operating system Microsoft Windows only Pentium 4
30. in the scientific literature and is explained in ref 1 and 2 In order to avoid the pile up effect 1 the detection rate of the laser trigger frequency must be lower than 5 or better 1 Anyway since in case of InGaAs modules the hold off time is large in the order of microseconds or even tens of microsecond and also the DCR is in the order of kc s the calculation of the correct module count rate to avoid pile up is less straight forward The key points to start are Module count rate should not be less than 576 of the laser frequency but only of the valid laser pulses i e the ones that were shined when the module was in the ON state The DCR dark counting rate should be subtracted since it is the signal count rate that should be less than 5 of the valid laser pulses Thus being CR the module counting rate Valid the number of valid laser pulses over an integration time T fue the laser frequency fiaser vaia the equivalent laser frequency considering only the valid laser pulses Tuo the hold off time Djaser 1 fraser Ome can aser write the following equations Tro Valid fiaser vatia T fiaser T CR T laser Ja e pulla Taser G R Tuo I Jiaser Then since the module counting rate is the sum of the DCR and the signal counting rate and it is only the latter that has to be less than for example 5 we obtain CR DCR lt 0 05 ya CR lt DCR 0 05 f aser valid 0 05 CR Ty
31. long time to the one that has been selected with SPAD Preset or directly input in the Advanced mode 2 The SPAD LED will become first yellow and afterwards green when the right bias voltage has been applied to the detector Micro Photon Devices S r l Italy All Rights Reserved 24 USING THE INGAAS MODULE 3 The GATE LED becomes green to indicate that the SPAD has been biased above breakdown Now the module is ready to be used in the experimental set up During the module functioning the trigger and gate parameters can be easily modified simply by changing them and uploading them to the module through the Update Configuration button Before changing the SPAD Preset currently in use the SPAD must be tuned off by using the Turn Off SPAD button 3 1 4 End of measure and powering off the module When the measurement ends and the InGaAs Single Photon Detection Module is not needed anymore the module must be powered down correctly in order to prevent detector damages The correct procedure is the following one 1 Press the Turn Off SPAD button and wait until the SPAD LED goes off 2 Repeat this operation for any connected module thought the respective module tab 3 When all the SPADs have been turned off close the program A message warns the user if there are modules still running when the software is closed If this happens please go back to the software and turn off these SPADs or carefully read the following chapter 3
32. ly the smallest amount of pressure when wiping the surface with lens tissue paper Micro Photon Devices S r l Italy All Rights Reserved 3 GETTING STARTED 1 3 The Control Unit s Front Panel InGaAs InP Single Photon Detection Module Control Unit All D PHOTON VALID TRIGGER TRIGGER MICRO PHOTON DEVICES OUT GATE OUT IN D The control unit is the same independently on the type of the Detection Head free running or gated 1 PHOTON OUT output SMA connector a digital pulse is generated for each detected photon the output is a NIM pulse which means that it must be 50 Q terminated and that the low logic level is 0 V and the high logic level is 800 mV The falling edge of the pulse marks with very low jitter the photon arrival time 2 VALID GATE output SMA connector outputs the effective SPAD status it is in the high logic level when the SPAD is ON or in the low logic level when the SPAD is OFF due to the hold off The output conforms to a LVTTL standard 3 TRIGGER OUT output SMA connector USE ONLY when a GATED MODE detection head is attached outputs the internal trigger reference signal used to periodically enable the SPAD Normally disabled it is enabled only when internal trigger is selected from the user interface The pulses are LVTTL standard 4 TRIGGERIN input SMA connector USE ONLY when a GATED MODE detection head is attached if an external trigger is needed then the signal must
33. mperatures is advised only for overvoltages equal to or lower than 5V moderate count rates and when the detection head is mounted on a very good heat sink In case the detection head cannot reliably keep such low temperature it will shut down itself with a warning In this case it is advised either to use temperatures higher than 233 K or to improve the module heat dissipation Don t warn for temperature lower than 233 K deactivates the warning message when you operate the SPAD at temperatures lower than 233 K By pressing Help on the menu bar the menu shown in Figure 2 5 will appear e InGaAs InP Single Photon Detection Module File Settings About MPD website Ca Gated Mode User Manual M i Free Running Mode User Manual mmm Jf Check updates automatically Figure 2 5 Help menu Micro Photon Devices S r l Italy All Rights Reserved 13 THE CONTROL SOFTWARE User Manual update is available Would you like to update it now Figure 2 6 Software Update left and User Manual update right dialogue boxes The Help menu lists the following items About when pressed a dialogue box showing the program name version and copyright will appear MPD website when pressed the default web browser will open on the MPD webpage Gated Mode User Manual when pressed the default PDF reader will be opened and the InGaAs user manual for the Gated mode module version will
34. mporal response low jitter with moderate DCR gives you almost the best possible efficiency and timing jitter of the module at the expense of high DCR but still not the highest SPAD Preset selection can be changed only when the detector is off Thus you have to use the Turn Off SPAD button if the diode is active Modifications are applied at the next start of the detector i e using the Apply Settings and Turn On SPAD button If you need a more specific configuration there is the possibility to manually set the detector temperature excess bias and hold off time by selecting the Advanced preset With this preset Micro Photon Devices S r l Italy All Rights Reserved 17 THE CONTROL SOFTWARE the Temperature Excess Bias and Hold Off controls shown for example in Figure 2 9 and highlighted in Figure 2 12 become active and the user can enter the desired values SPAD Preset Best Timing Lowest Noise Low Noise Better Timing lt Best Timing Advanced Figure 2 11 SPAD Preset configurations drop list menu Temperature Excess Bias Hold Off 233 0K 4 0 20us Figure 2 12 Advanced SPAD configuration with fancy values Normally these controls display the set values but do not allow their modification In Advanced mode instead you can configure these three parameters into the range and with the steps defined in the Specifications chapter By inserting a value outside these limits the program automatically
35. nP Statt SN00048 MICRO PHOTON DEVICES Single Photon Detection Module DETECTION MODULE CONTROL MODULE STATUS OVERVIEW e E W Turn Off SPAD 2 Update Configuration CU SN 00029 DH SN 00048 GATE SETTINGS SPAD Temp 2449K This detection head works in free running mode TEC Controller SPAD SETTINGS a SPAD Preset Temperature Excess Bias GATE Advanced 233 0K 4 0V Detection Head MANAGE MODULE CONFIGURATIONS pieds ni CH Save to file m Load from file L7 Load from module Lee UC devi Ready Summary Detection Head SN00048 on SN00029 module connected Module tab screenshot after having turned on the SPAD and with the Advanced SPAD preset selected Note that the temperature setting is blue and that the Update Configuration button is active current SPAD temperature 245 K but the desired one is 233 K 2 4 2 SPAD Settings With this panel you can select a SPAD configuration that is a particular combination of detector temperature excess bias and hold off time Under SPAD Preset drop list menu shown in Figure 2 11 there are four preset configurations which lead to different detector pertormances in particular Lowest Noise Low Noise Better Timing Best Timing it sets almost the lowest achievable DCR at the expense of detection efficiency and timing resolution offers higher detection efficiency and still low DCR allows to obtain high efficiency and a good te
36. ns Autodetect and Accept Config The Start tab has also a menu bar which is always present and does not change independently on which tab is currently selected This menu bar has three menus File Settings and Help InGaAs InP Single Photon Detection Module So mj File Settings Help MPD InGaAs InP Single Photon Detection Module Detected Modules COM name Connected Module Custom name COM SN00048 on SN00029 SN00048 Start Summary Figure 2 1 Start tab screenshot with one detected module 2 2 1 Detected Modules table In this table are reported all the detected connected modules For each ones the software displays the Detection Head and Control Unit Serial Numbers and to simplify the system identification a custom name can be assigned By default the Custom Name corresponds to the Detection Head s serial number and is linked to the Detection Head and saved in the PC so it is recalled every time this specific Detection Head is connected to the PC This is true even if the Detection Head is connected through a different Control Unit Of course any name can be chosen as Custom Name If the software has detected all the connected modules and the user has associated all the custom names the Accept Config button can be clicked on By accepting the configuration the software will create additional tabs one for each detected module as is shown in Figure 2 2 Micro Photon Devices S r l Italy All Rights Reserved
37. ntrol Unit by using the orange wide bandwidth cable and inserting it in the inlets present in the back panel of both devices It must be ensured that the latches are both locked in the correct position Take care in cable routing minimum bend radius is 5mm and first bend must be at almost 100 mm from the end connector Connect the power cord between the power inlet in the back panel of the Control Unit and the power line supply Connect the USB cable from the Control Unit to the PC Switch on the Control Unit using the ON OFF switch on the rear panel Micro Photon Devices S r l Italy All Rights Reserved 23 USING THE INGAAS MODULE After this last operation the fan starts rotating and the module is ready to accept commands from the PC controlling program 3 1 2 Program start and device acquisition By following the instructions outlined in Chapter 2 the control software can be installed in the computer and then can be started After the splash screen reporting the software version number the Start Tab will be shown The software automatically searches the connected modules at startup so when the splash screen disappears all the connected modules should be displayed in the Detected Modules table as shown in Figure 2 1 if this does not happen by clicking the AutoDetect button it is possible to force the program to retry the search For each connected module a custom name can be assigned This is very useful for identitying the
38. o fiaser and after few simple mathematical calculations we finally get 2 0 05 fiaser DCR 1 0 05 Tyo fraser If DCR is much smaller than the actual CR then it can be ignored in the above equations If one wants to reduce even more the pile up effect he can substitute 0 05 with 0 01 1 distortion Finally in order to simplify the equations and to be conservative the afterpulsing effect was not included Micro Photon Devices S r l Italy All Rights Reserved 28 USING THE INGAAS MODULE 3 3 Troubleshooting Whenever a problem occurs during the use of the InGaAs single photon counter please follow the directions contained in FlowChart 0 Please call MPD for assistance only if your problem is not listed here if the flowchart directly tells you to do so or if the error persists despite the troubleshooting efforts Yes A status LED is red See flowchart 1 No Control Unit fan No is rotating See flowchart 2 Yes Module does not appear in the Connected Modules List Yes See flowchart 3 No No signal at Yes outputs See flowchart 4 No Call MPD FlowChart 0 Micro Photon Devices S r l Italy All Rights Reserved 29 INGAAS MODULE USING THE e npouJ y uwopinus pedoud 0 ejqeo gsn U98 91 o JequueuJe J G Lc 8 pea Ajjnjoseo eseo d epouJ euojepuejs Ul ejnpoui y Buisn ase no Sal einpoui au yo youms gjes ued noA c
39. rds work in the so called reverse mode When connecting all the instruments it is very important to verify the voltage levels and the polarity of all the involved signals and to attenuate invert them if necessary in order to comply with the inputs absolute maximum ratings In order to ensure that the photons emitted by the sample impinge on the detector when the gate has been enabled it is necessary to take particular care to the signal propagation delays inside the cables and in the instruments included the InGaAs control unit see Chapter 4 for the actual numbers InGaAs InP Single Photon Detection Module Control Unit PHOTON VALID TRIGGER TRIGGER OUT GATE OUT IN Q TCSPC system START STOP zue torn Zine een VOA Trigger In 1 Figure 3 2 Simple setup for a photon timing measure green optical signals pink electric signals pa Trigger Out Micro Photon Devices S r l Italy All Rights Reserved 27 USING THE INGAAS MODULE The TCSPC technique is normally adopted in order to correctly reconstruct the shape of the temporal response of fast pulses or a fast decaying fluorescence pulses like in our example by accurately measuring the photon arrival times and not simple measuring number of counts in a period of time In order to do this using the TCSPC technique it must be guaranteed that only a single photon reaches the detector for every single laser pulse This is commonly known
40. rror see immediately paragraph 3 3 before powering off the module In case of all the other errors the module turns off the SPAD and does not accept any more commands thus it is necessary to switch off the module Before switching it on and detecting it again it is advisable to solve the cause of the error In some rare cases it might happen that after having turned off the SPAD the SPAD LED remains orange indicating that the detector s turning off procedure is taking longer than expected see Figure 2 16 In this case please press the OK button to start an internal diagnostic routine In case the tests will end successfully the window shown in Figure 2 17 left will appear please press OK to continue In case the tests will end with a false alarm detection the window shown in Figure 2 17 right will appear please follow the indicated procedure in order to safely power off the module and reboot the whole detection system Micro Photon Devices S r l Italy All Rights Reserved 20 THE CONTROL SOFTWARE InGaAs Single Photon Detection Module IM mje xl InGaAs InP QD Single Photon Detection Module DETECTION MODULE CONTROL MODULE STATUS E OVERVIEW Turn Off SPAD lt gt Update Configuration CU SN 00011 DH SN 00003 GATE SETTINGS Trigger Source Threshold Valid Edge Gate Width SPAD Temp 244 0K TEC External 0 00V Rising Edge 0 00s Controller SPAD SETTINGS SPAD SPAD Preset Temperature Excess Bias GATE Advanced Y 2
41. s Alberto Tosi Alberto Dalla Mora Franco Zappa and Sergio Cova Single photon avalanche diodes for the near infrared range detector and circuit issues Journal of Modern Optics 56 2 3 299 308 2008 http dx doi org 10 1080 09500340802263075 Alberto Tosi Alberto Dalla Mora Simone Tisa Fabio Acerbi Franco Zappa and Sergio Cova InGaAs InP SPADs for near infrared applications device operating conditions and dedicated electronics Proc SPIE 7681 Advanced Photon Counting Techniques IV 76810R April 28 2010 http dx doi org 10 1117 12 850696 Paper on the InGaAs Single Photon Detection Module Alberto Tosi Adriano Della Frera Andrea Bahgat Shehata and Carmelo Scarcella Fully programmable single photon detection module for InGaAs InP single photon avalanche diodes with clean and sub nanosecond gating transitions Rev Sci Instrum 83 013104 2012 http dx doi org 10 1063 1 3675579 Micro Photon Devices S r l Italy All Rights Reserved 8 THE CONTROL SOFTWARE CI 2 The Control Software This is the operator s reference chapter which contains information about for the software front panel of the InGaAs Single Photon Detection Module 2 1 Software Installation and Startup Complete the following steps to install the controlling software for Windows Log in as system administrator or as a user with administration privileges Disable any automatic virus detection programs before you in
42. s other serial instruments that do not like the CS command sent by the program in order to detect connected modules Static COM number control when the auto detect checkbox is disabled the COM port to which the photon counter has been connected must be specified in this field COM Exclusion List it lists the COM port numbers that have to be excluded from the automatic detection process Use comma as number separator Note You have to restart the program in order to make the changes active Micro Photon Devices S r l Italy All Rights Reserved 12 THE CONTROL SOFTWARE Advanced Settings Advanced Mode Keep Advanced Preset Don t warn for Advanced Preset Temperature J Enable lower temperature down to 228 K Don t warn for temperature lower than 233 K ees Figure 2 4 Advanced Settings By pressing the second item of the Settings menu a configuration window shown in Figure 2 4 will appear Inside this window there are the following controls Keep Advanced Preset when selected the program retains the last Advanced Preset settings also when you temporary switch on other presets Otherwise these settings are overridden Don t warn for Advanced Preset deactivates the warning message when you switch to or you load an Advanced Preset Enable lower temperature down to 228 K allows to set as SPAD temperatures values below 233 K but higher than 228 K The use of the detector at such low te
43. stall Some virus detection programs could interfere with installation Insert the USB key and copy the Install_for_Windows folder in a temporary location for example your Desktop Double click on the file named setup exe located inside the folder you just copied Follow the instructions on the screen until the installer ends Connect the module at the PC with the procedure detailed in Chapter 3 1 1 Windows will automatically recognize the device and install the correct drivers If a found new hardware window appears select the option to automatically download recommended drivers from internet For this reason the computer on which the drivers will be installed MUST BE CONNECTED to the internet The drivers will create a virtual serial COM associated with the InGaAs InP single photon counter Once completed you can start the controlling software from Windows Start Menu gt Programs gt MPD gt InGaAs Single Photon Detection Module Remove the temporary install folder Micro Photon Devices S r l Italy All Rights Reserved 9 THE CONTROL SOFTWARE 2 2 Start Tab When the software is started for the first time the window illustrated in Figure 2 1 is shown This window will have two tabs the Start tab and the Summary tab With the Start tab it is possible to detect and name all the InGaAs Single Photon Detection Modules attached to the PC where the controlling software runs It consists of a Detected Modules table and two butto
44. strument NIM Output Photon Out 37 4 4 Memali MAI GOCE oent 3 4 5 Gate Window and Hold Off programmability 37 4 6 Signal Propagation NIMES ierit ose I seien meta 38 SWAMP elg ET 39 4 8 General SpecificatloriS EE 40 4 9 System Requirements for Software 40 5 Chalgeloguu C Micro Photon Devices S r l Italy All Rights Reserved GETTING STARTED CI 1 Getting Started This chapter provides the introduction on the MPD InGaAs Single Photon Detection Module that will help you get acquainted with the product It also includes the installation and configuration procedures that will support you in getting started with the system 1 1 Introduction The InGaAs single photon detection module is built around a Peltier cooled InGaAs InP Single Photon Avalanche Diode SPAD for the detection of near infrared single photons from 900 nm up to 1700 nm The module includes a programmable frequency and pulse generator for gating the detector a front end circuit for photodetector s avalanche sensing a fast circuit for detector s avalanche current quenching and operative bias voltage resetting and some sub circuits for signal conditioning All the main parameters are adjustable by the user through the software interface in order to match the requirements of the
45. the SPAD settings is the Advanced preset and SPAD presets can be changed only when the SPAD is in the OFF state Thus this button becomes active only when the Advanced preset has been set and at least one SPAD setting has been modified after the turning ON of the diode New values are uploaded simply by pressing this button Values shown in the module tab that do not correspond to the ones already loaded in the InGaAs module because for example they have been just changed by the user are highlighted in blue as shown in Figure 2 10 Finally it is worth noting that any change of the SPAD settings may require a detector power off and a consequent power on transient that is carried out automatically by the module Turn Off SPAD button if the SPAD is on this button replaces the Apply Settings and Turn On SPAD one as shown in Figure 2 9 In order to shut down the detector this button must be clicked and the user has to wait until the SPAD status LED in the Module Status Overview is off Note You MUST press Turn Off SPAD and WAIT until the SPAD status LED is off before switching off the complete module by using the power switch located on the module rear panel If this procedure is not followed the SPAD detector may be permanently damaged Micro Photon Devices S r l Italy All Rights Reserved 16 THE CONTROL SOFTWARE Figure 2 10 5 InGaAs InP Single Photon Detection Module m E File Settings Help e MPD InGaAs I
46. tly of the type of the used detection head free running or gated Detection Head LED it turns red when there is no communication with the Detection Head or when the maximum Gate Width is not satisfied external trigger Otherwise it is green Control Unit LED it turns red only when there is no communication with the Control Unit Otherwise it is green System Ready LED during the normal functioning of the whole system it is green it turns red only when an error inside the module is detected Others indicators in this section are e CU SN MPD serial number of the connected Control Unit e DHSN MPD serial number of the connected Detection Head SPAD Temp the current temperature of the detector in Kelvin It is active only when the TEC controller is active in all the other cases it does not show anything There is also a status bar at the bottom of the module window shown for example in Figure 2 10 it reports the module loaded configuration or eventually the error messages MODULE STATUS OVERVIEW CU SN 00029 DH SN 00048 SPAD Temp 244 9K TEC Controller SPAD GATE EEE Detection Head Control gea Unit System Ready Figure 2 13 Module Status Overview indicators during detector power on Micro Photon Devices S r l Italy All Rights Reserved 19 THE CONTROL SOFTWARE MANAGE MODULE CONFIGURATIONS CH Save to file Ir Load from file rs Load from module Figure 2 14 Manage Module
47. tus LEDs are green Yes No Lines are 500 terminated Yes Which output does not work Trigger Out Valid Gate or Photon Out Yes Trigger is external No Power off the module using the right procedure Disconnect and reconnect the orange cable between Control Unit and Detection Head taking care on routing see 3 1 1 Micro Photon Devices S r l Italy INGAAS MODULE No Donda Head hes Press Update Parameters And Turn On Detection been activated Head button Yes Use 50Q terminations pa i equal to 0 Yes No Change Gate Width to Wait until all LEDs a different value are green Trigger is No Call MPD and report an external internal trigger problem Yes Call MPD and report an Trigger Out work only external trigger problem with internal trigger Yes Threshold is Yes External signal meets correctly setted specifications in 84 1 No No Change threshold Change external and update settings signal accordling to them Yes a ma iban Call MPD and report a and check if the problem problem on Photon Out path persists FlowChart 4 All Rights Reserved USING THE INGAAS MODULE 3 4 Bibliography 1 Lakowicz J R Priciples of Fluorescence Spectroscopy 3 Edition Springer New York 2006 2 Connor D V O Phillips D Time correlated Single Photon Counting Academic Press London 1984 3 PicoHarp 300 by PicoQuant GmbH http w
48. ww picoquant com products picoharp300 picoharp300 htm 4 SPC 130 by Becker and Hickl GmbH http www becker hickl de tcspc htm spc130 Micro Photon Devices S r l Italy All Rights Reserved 35 SPECIFICATIONS 4 Specifications The specifications of the InGaAs Single Photon Detection Module are provided in this chapter 4 1 Instrument Input Trigger IN Note Do not use when the control unit is connected to Free running detection head Coupling DC to 133 MHz if Ton 10 ns DC to 25 MHz if Tou 10 ns Damage CEA vis Minimum Slew Rate 5 V us Threshold Level Range Resolution Accuracy Trigger Slope Minimum Pulse Width 2ns 4 2 Instrument LVTTL Outputs Trigger Out Valid Gate Note when the CU is connected to a Free running detection head Trigger Out is disabled Amplitude 073 3 V 400 mV Required Load 50 O fixed DC impedance Rise Fall Time 20 80 Valid Edge Maximum frequency also limited by condition 1 frric gt Ton min GATE OFF time see paragraph 4 5 Micro Photon Devices S r l Italy All Rights Reserved 36 SPECIFICATIONS 4 3 Instrument NIM Output Photon Out Amplitude 0 16 mA on 50 Q 0 0 8 V Required Load 50 O fixed DC impedance Valid Edge Falling Time 20 80 400 ps NIM pulse width 4 4 Internal Trigger Note Not enabled if the CU is connected to a free running detection head Output frequencies under 1 MHz 200 400 Hz 500 80
49. y connected module in a single screenshot furthermore it reports the status of every device Since a maximum of four InGaAs Single Photon Detection Modules can be connected to a single PC there are four columns that are filled with the appropriate parameter status indicated by the row header Since the InGaAs control SW is able to manage both free running and gated detection heads the Summary Tab will indicate accordingly which detection head DH is a free running one and which one is gated on the line named Trigger Configuration This screen is only a summary the values contained into the table cannot be modified in this tab in order to change the parameters the correct Module Tab must be selected and the settings must be adjusted there The Summary Tab is also only available when the software is in Multiple Module Mode since in Single Module Mode all the reported information is already presented in the unique Module Tab present E InGaAs Single Photon Detection Module xj VID k Ins ich poron serien Single Photon Detection Module alpha beta COM Port COM50 COM52 Module IDs SN00001 on SN00010 SN00003 on SN00011 SPAD Configuration Advanced Advanced Excess Bias 7000 mV 3200 mV Hold Off 10 01 us 15 00 us Temperature 270 0 K 243 0 K Trigger Configuration Free Running External Gate Frequency SE cs dal Trigger Threshold 0 mV Valid Edge Rising
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