High Performance Photon Counting User Handbook DPC-230 16 Channel Photon Correlator Becker & Hickl GmbH
(c) Becker & Hickl GmbH
Becker & Hickl GmbH April 2008 High Performance Photon Counting Tel. +49 / 30 / 787 56 32 FAX +49 / 30 / 787 57 34 http://www.becker-hickl.de email: info@becker-hickl.
II Becker & Hickl GmbH Nahmitzer Damm 30 12277 Berlin Germany Tel. +49 / 30 / 787 56 32 FAX +49 / 30 / 787 57 34 http://www.becker-hickl.com email: info@becker-hickl.com April 2008 This handbook is subject to copyright. However, reproduction of small portions of the material in scientific papers or other non-commercial publications is considered fair use under the copyright law. It is requested that a complete citation be included in the publication.
Contents Contents Introduction ...............................................................................................................................................1 Principle of Data Acquisition ....................................................................................................................1 Time-to-Digital Conversion.................................................................................................................1 DPC-230 Architecture .........................
IV Loading Setup and Measurement Data ................................................................................................50 Predefined Setups ................................................................................................................................51 Converting FIFO Files .........................................................................................................................53 Format of Time-Tag Data Files .................................................
Introduction The DPC-230 photon correlator card records absolute photon times in up to 16 parallel detection channels. Depending on how the photons are correlated, fluorescence correlation (FCS), fluorescence cross correlation (FCCS), photon counting histograms, or waveforms of the light signals are obtained. In combination with optical scanning time-resolved images can be recorded. The maximum time resolution of the recording is 165 ps per time channel.
2 Principle of Data Acquisition ring is read, and used to determine the detection time. Times longer than the reference cycle time are determined by counting the reference cycles. G1 Ring Oscillator G2 G3 Gn Counter Readout Register Input Pulse D C D C D C D C D C Encoder fine time coarse time Fig. 2: Principle of a digital TDC.
Principle of Data Acquisition 3 When a measurement is started the TDCs in all active channels simultaneously start running. Any event detected at one of the 16 LVTTL inputs or at one of the four CFD inputs triggers a time readout from the TDC of the corresponding channel. The time is first buffered in an internal first-in-first-out (FIFO) memory of the TDC chip. The data from the internal FIFO are then written into an external FIFO that buffers up to 4 million events.
4 Principle of Data Acquisition Three of the CFD channels are used for the detector signals. The CFD output pulses of these channels are fed directly into the ECL inputs of the TDC chip. The fourth CFD input is used for the reference from the laser. Before the reference pulses enter the TDC chip they pass a frequency divider, FD, and a synchronisation circuit, SYNC. The divider ratio of FD is selectable and can be set to 1:1, 1:2, or 1:4.
Operation Modes Absolute-Timing Modes In the ‘Absolute Time’ mode every photon is characterised by its time from the start of the measurement and its input channel number. The interpretation of the data is merely a matter of the software. The different ways of analysing the data and the presenting the results are described below. The results can be built up online from the incoming data stream, or off-line from the time-tag data files. Please ‘Configuring the Runtime Display’, page 45.
6 Operation Modes tive brightness and the concentration ratio of the molecules to the measured PCH. The technique is also called ‘fluorescence intensity distribution analysis’, or FIDA. The theoretical background is described in [9, 10, 15, 17, 21, 23, 24]. The PCH/FIDA technique can be extended for multi-dimensional histograms of the intensity recorded by several detectors in different wavelength intervals or under different polarisation.
Absolute-Timing Modes 7 The autocorrelation (shown left) has a sharp peak at τ = 0. (The function correlates perfectly with itself). The slow fluctuations in I(t) represent themselves in a high correlation at medium τ. For τ longer than the typical time of the slow fluctuations G(τ) drops to very low values. The cross-correlation function of the two signals, I1 and I2, is shown right. The slow fluctuations in I1 and I2 have the same general appearance. However, the noise in I1 and I2 is different.
8 Operation Modes The procedure illustrated in Fig. 10 yields G(τ) in equidistant τ channels. The width of the τ channels is equal to the time-channel width of the DPC-230, T. The algorithm is known as the ‘Linear Tau’ algorithm. The equidistant τ channels result in an easily predictable statistics. This is a benefit if a model function is to be fitted to the correlation function.
Relative Timing Modes 9 of the excitation source, and the distribution of the events within the excitation period is built up. Thus, the multichannel scaler mode is a relative-timing mode. Multichannel scaler operation is illustrated in Fig. 12. The hardware structure is the same as in the ‘absolute time’ mode. However, one channel of the DPC is used as a reference channel. The reference channel receives synchronisation pulses from the light source.
10 Operation Modes result is the waveform of the light signal. Because three input channels are available in the TCSPC mode three signals from three detectors can be recorded simultaneously. Reference (not recorded) Ref. (not rec.) Reference (not recorded) Photon Time Reference (not recorded) Reference (not recorded) Reference (not recorded) Photon Time Reference (not recorded) Ref. (not rec.
Relative Timing Modes 11 Other applications of the absolute times in TCSPC data are multi-parameter single-molecule spectroscopy [19, 25, 31], burst-integrated lifetime (BIFL) experiments, and fluorescence intensity and lifetime distribution analysis (FILDA) [23]. Imaging The DPC-230 can be used for imaging applications. The sample is scanned by a focused laser beam, the photons are detected with their absolute or relative times, and the image is built up from the recorded data.
12 Operation Modes ton count rate. This makes the recording process more or less random. The recording is continued over as many frames as necessary to obtain the desired number of photons per pixel. There are many modifications of the principle shown in Fig. 14. Imaging is possible both in the multiscaler mode and the TCSPC mode. Other operations than FLIM calculation can be applied to the photon and pixel data, and several detectors can be used simultaneously. By storing the raw data, i.e.
Installation Computer In principle, the DPC-230 module can be installed in a PCI slot of any Pentium PC. However, the SPCM software runs the data transfer and the online-data processing in parallel ‘threads’. To achieve a reasonable data transfer and processing rate the computer should be one with a dual-core architecture. The graphics card should have 1024 by 628 resolution or more. Both table-top and tower versions can be used. However, the computer must accept a full-size PCI card.
14 Installation Fig. 16: Installation panels The installation works the same way as the installation from the CD. Check the boxes of the software components you want to install (Fig. 16, right). The operating software of the DPC is ‘SPCM’. If you operate the DPC together with the DCC-100 detector controller you need also ‘DCC’. The SPCM and DCC software components are all you need for DPC standard applications. The components are free and can be installed without any password.
Software Start 15 Fig. 17: Downloading the drivers from the bh web site Open www.becker-hickl.com and click on ‘Software’. On the ‘Software’ page, click on ‘TCSPC Modules’, ‘Drivers’. Then click on ‘Setup’ and download the drivers. Software Start When the module is inserted and the driver is installed, start the SPCM Software. The initialisation panel shown in Fig. 18, left should appear. The installed modules (there can be up to four) are marked as ‘In use’.
16 Installation Starting the SPCM Software without a DPC-230 Module You can use the Multi SPC Software without a DPC module. In its start window the software will display a warning that the module is not present, see Fig. 19, left. Fig. 19: Startup panel in the simulation mode (without a TCSPC module) To configure the software for the desired module type, click into the ‘Change Mode’ field and select the module type (DPC-230) from the list which is opened (Fig. 19, right).
Operating the DPC-230 LVTTL Inputs The LVTTL inputs of the DPC-230 are designed to receive single-photon pulses from SPAD (single-photon avalanche photodiode) modules. LVTTL means ‘low voltage TTL’, i.e. the inputs are triggered by signals as low as +1.5 V. The pulse duration can be as short as 2 ns. The location of the LVTTL inputs at the DPC board are shown in Fig. 20. The signals are fed trough the back panel of the computer via cable adapters (Fig. 20, middle and right). Fig.
18 Operating the DPC-230 Manufacturer Type id Quantique MPD Perkin Elmer Hamamatsu id 100-xx PDM-xxCT SPCM-AQR H7421-40 Pulse Amplitude +2 V +2 V +3.5 V +3V Pulse Width 20 ns 20 ns 35 ns 30 ns Remark Versions of different area available Use TTL output.
CFD Inputs 19 Connecting PMTs to the CFD Inputs PMTs use secondary-electron emission to multiply a single photoelectron by a factor of 106 to 108. The output pulses of a PMT are negative, with a average amplitude between 10 mV and 100 mV and a duration between 300 ps and a few ns. Due to the random gain mechanism the pulse amplitude varies randomly. The variation can be on the order of 1:10. Moreover, there are a large number of small-amplitude background pulses from the dynode system of the PMT.
20 Operating the DPC-230 Manufacturer bh bh Hamamatsu Hamamatsu Hamamatsu Type PMC-100-201) PMC-100-011) H7422P-401) H5773P-00, -01 R3809U Preamplifier internal internal HFAC-26-2 HFAC-26-10 HFAC-26-01 HV / Gain 100 %2) 95%2) 90%2) 0.9V3) -3000V CFD Thresh.
Typical Applications Fluorescence Decay Measurements A typical experiment setup for fluorescence decay measurement is shown in Fig. 26. The sample is excited by a bh BDL-SMC picosecond diode laser [5]. The pulse repetition rate is 20, 50, or 80 MHz, the pulse width between 50 and 90 ps. The laser is operated from a simple +12V wall-mounted power supply. The laser power is controlled by a signal from the bh DCC-100 detector controller [3].
22 Typical Applications The right part of the panel shows the discriminator parameters of the CFD inputs and the TDC parameters. The optimal discriminator settings depend on the detectors; the parameters shown are typical of the bh PMC-100 module. The TDC parameters contain the time-channel width, the number of time channels, and the time range of the recording. Moreover, the curves can be shifted in time by applying an offset to the TDC times. Fig.
Luminescence Decay Measurement in the Microsecond Range 23 Fig. 29: Trace parameters and display parameters recommended for fluorescence decay measurement Fig. 30: Decay curves recorded with the setup parameters shown in Fig. 27 through Fig. 29 Luminescence Decay Measurement in the Microsecond Range A suitable setup for luminescence decay measurements in the µs range is shown in Fig. 31. For extremely long decay times the laser pulse repetition rate must be reduced to a few 10 kHz or less.
24 Typical Applications The luminescence light is detected the same way as for fluorescence decay measurement. The reference pulses for the DPC-230 are obtained from a second output of the DDG-200 pulse generator. For microsecond lifetime measurement the DPC-230 is operated in the multiscaler mode. The system parameters are shown in Fig. 32. The other parameters are the same as for fluorescence decay measurement. A typical result is shown in Fig. 33. Fig.
Fluorescence Correlation 25 A typical optical setup is shown in Fig. 34. A CW laser beam is focused into the sample through a microscope objective lens. The fluorescence light from the sample is collected by the same lens, separated from the laser by a dichroic mirror, and fed through a pinhole in the upper image plane of the microscope lens. Light from above or below the focal plane is not focused into the pinhole and therefore gets substantially suppressed.
26 Typical Applications stopped after a defined acquisition time. Activate the ‘Stop T’ button if you want to stop after a specified time. ‘Max Buffer Size’ defines a buffer in the RAM of the computer. If enough RAM is available the buffer size should be as large as or larger than the specified file size. The SPCM software then stores the time-tag data into the RAM before it writes them to the hard disc. The data readout is then not slowed down by hard disc operations.
Fluorescence Correlation 27 The curves to be displayed in the display windows for the accumulated counts, FCS curves, and MCS traces are defined under ‘Trace Parameters’. Each display window has its own trace parameters. To open the trace parameters, click on ‘Display’, ‘Trace Parameters’. A click into one of the curve windows selects the right trace parameter set. Alternatively, you can click in the desired curve panel with the right mouse key, and select ‘Trace Parameters’.
28 Typical Applications Fig. 40: Cross-Correlation between two detector channels Picosecond Fluorescence Correlation Fluorescence correlation down to the picosecond range has first been described in [12]. The authors used two bh SPC-130 modules with synchronised macro times, and included the TAC times in the calculation. The time resolution of this system is extremely high. The timechannel width can be as small as 820 fs; the electronic IRF width is about 5 ps FWHM.
Anti-Bunching 29 Anti-Bunching Anti-bunching information is contained in picosecond fluorescence correlation data, see Fig. 41. However, anti-bunching curves can also be recorded via the classic Hanbury-Brown-Twiss start-stop experiment [14]. The light is split in two or more components and fed into separate detectors. The photons of one component are used as start pulses, the photons of another detector as stop pulses.
30 Typical Applications Fig. 43: Input configuration for a classic anti-bunching start-stop experiment To see the desired start-stop histograms, activate the traces for the input channels (i.e. the stop channels) used in the trace parameters. The parameters for the two-detector setup defined in the input configuration are shown in Fig. 44. A result obtained from a Rhodamine 110 solution is shown in Fig. 45. Fig.
Fluorescence Lifetime Imaging 31 Fig. 46: Start-stop histogram and ps correlation obtained in the same measurement Fluorescence Lifetime Imaging The general principle of the TCSPC FLIM mode of the DPC-230 is the same as for the FIFO Imaging mode of the bh SPC modules [2]. The DPC-230 records the photons detected in one detector together with the synchronisation pulses from the scanner into a common time-tag data stream.
32 Typical Applications The scan clock pulses (pixel clock, line clock, frame clock) of the microscope are connected into three LVTTL channel of TDC 1. Thus, TDC 1 records the times of the scan clocks, TDC 2 the times of the photons and the times of the laser pulses. The FLIM image is reconstructed from these data. The system parameters for FLIM operation are shown in Fig. 48. The DPC works in the ‘TCSPC FIFO’ ‘FIFO Imaging’ mode.
Fluorescence Lifetime Imaging 33 the FLIM image. Moreover, many microscopes send a frame clock pulse some pixels before the start of the useful part of the line. These pixels can be excluded from the recording by defining a ‘Left Boarder’ larger than zero. Settings typical for FLIM with the Zeiss LSM 510 and LSM 710 microscopes [7] are shown in Fig. 50, right. Fig. 50: Scan synchronisation parameters. Left: FLIM image has same pixel numbers as microscope scan.
34 Typical Applications Fig. 52: Fluorescence lifetime image recorded with DPC-230 and bh DCS-120 confocal scanning FLIM system [4]. Data analysed by SPCImage data analysis routines of SPCM software [4, 6]. Intensity image, lifetime image, decay curve and fit at cursor position. Luminescence Lifetime Imaging in the Microsecond Range Fluorescence lifetime imaging in the microsecond range requires low repetition rate of the excitation pulses. Low repetition rate causes two problems.
Luminescence Lifetime Imaging in the Microsecond Range 35 beginning of each pixel. The pixel time is made long enough to observe the full luminescence decay before the scanner goes to the next pixel. Because of the low laser repetition rate the DPC-230 is best operated in the ‘Multiscaler Imaging’ mode. This makes a delay in the SNC path unnecessary. Moreover, multiscaler operation does not require any gating of the stop pulse with the previously detected photons (see Fig. 4).
36 Typical Applications Fig. 56: Input configuration panel. Left: PMT on CFD 3, reference on CFD 4. Right: SPADs on LVTTL 5 through 20, reference on LVTTL 4. Fig. 57 shows a luminescence lifetime image of a luminescent glass embedded in a Rhodamin 6G solution. The image was recorded by a bh DCS-120 confocal scanning FLIM system [6] and analysed by the bh SPCImage routines embedded in the SPCM software. The glass fluorescence has a triple-exponential decay, with components of 140 ns, 689 ns, and 1,79 µs.
SPCM Software The DPC-230 comes with the ‘Multi SPC Software’, or ‘SPCM’ operating software. The SPCM software is not only used for the DPC-230 but also for all bh SPC (TCSPC) modules. It allows the user to operate up to four DPC-230 modules, or up to four SPC-630, -730, -830, 130, 140, or 150 modules. The SPCM software includes measurement parameter setting, measurement control, loading and saving of measurement and setup data, and data display and evaluation in 2-dimensional and 3-dimensional modes.
38 SPCM Software A typical main panel of a correlation measurement in the ‘Absolute Time’ mode is shown in the upper row, left. It shows the photon numbers accumulated in four detection channels, the intensity trace of one channel, correlation between two channels, and photon counting histograms of two channels. A TCSPC measurement is shown in the upper row, right. It shows a fluorescence decay curve and an IRF recording. The recordings were taken in different ‘Measurement Pages’.
Configuring the SPCM Main Panel 39 The Display Parameters (shown left) allow you to define how your results will be displayed. The upper part refers to the display of curves, the lower part to the display of images or other multi-dimensional data. The range of the count numbers to be displayed can be defined in the upper left. The style of the curves displayed can be defined under ‘Trace’ and ‘2D display’. The colours of images are defined in the lower left.
40 SPCM Software Fig. 62: Select panel for display size, cursor display, and display and trace parameters It can happen that a display window has disappeared behind the edge of the screen or otherwise got out of control. (This can happen if a file from a dual-screen system is loaded in a computer with only one screen.) In that case, click into ‘Display’, and ‘Default Size and Position’. When the window is back in the screen area, set it to ‘Scale Contents on Resize’, see Fig. 63. Fig.
Configuring the SPCM Main Panel 41 instrument configurations several data sets may have been recorded. In this case click on the display window that shows the data to be analysed, and then click on ‘Send Data to SPCImage’, see Fig. 65. For details of the SPCImage data analysis, please see [4] and [6]. Fig. 65: Sending data to the data analysis.
42 SPCM Software lost. Strictly, such data cannot be correlated any more. However, as long as only a few overflows occurred correlation within one and the same TDC may still possible without noticeable errors. However, data with more than 10 overflows are useless for correlation. Device State ’Device state’ informs about the general status of the DPC-230 see Fig. 69. Fig.
System Parameters of the DPC-230 43 System Parameters of the DPC-230 The system parameters panel of the DPC-230 is shown in Fig. 70. The panel contains separate sections for the measurement control parameters and the hardware settings of the CFDs and the TDCs. Fig. 70: System parameters of the DPC-230 Operation Mode The operation mode of the DPC is selected by two parameters. The first parameter determines the hardware configuration, the second one the way the photon data are interpreted.
44 SPCM Software next reference pulse (see ‘Relative Timing’, page 3). The data of the detector channels can be interpreted either as single waveforms (‘Single’), as oscilloscope traces (‘Oscilloscope’), or as fluorescence decay curves plus fluorescence correlation data (‘FIFO’). The ‘FIFO’ option is similar to the FIFO mode of the bh SPC modules [2]. Moreover, images can be acquired by recording synchronisation pulses from a scanner together with the photons (‘FIFO Image’).
System Parameters of the DPC-230 45 full. Although this may slow down the data transfer from the SPC module the loss is by far smaller than for memory swapping. You may switch off the storing of the time-tag data altogether. However, in this case the software discards the raw data and delivers (and stores) only the results specified under ‘Configure’ and. It is then impossible to run any later data processing on the single-photon data. The option should therefore be used with care.
46 - SPCM Software Calculation of photon counting histograms for the individual detectors (‘FIDA’). The sampling time interval is specified on the right. Calculation of lifetime histograms (FILDA) for all detectors. The sampling time interval is specified on the right. Intensity traces (MCS) for the individual detectors. For all functions specified for runtime display individual display windows are provided in the main panel, see ‘Configuring the SPCM Main Panel’ page 37.
System Parameters of the DPC-230 47 Both TDC chips can be switched on and off by the ‘active’ button. If one of the TDCs is not used it should be switched off to avoid unnecessary software actions. For both TDCs the inputs can be switched to ‘LVTTL’ or ‘CFD’. Each TDC either has 8 LVTTL inputs or 2 CFD inputs. The LVTTL configuration is shown in Fig. 77, left, the CFD configuration right. It is possible to combine LVTTL operation in one TDC with CFD operation in the other. Fig.
48 SPCM Software Fig. 79: SYNC frequency divider setting. The parameters determines the number of signal periods recorded in the TCSPC mode TDC Parameters The TDC parameters determine the recorded time interval and the number of time channels in the TCSPC mode and in the multichannel-scaler mode. The parameters are shown in Fig. 80. Fig. 80: Left: TDC parameters. Right: Selecting the number of time channels from a list ‘Range’ is the recorded time interval.
Saving Setup and Measurement Data 49 Saving Setup and Measurement Data The ‘Save’ panel is shown in Fig. 81. It contains fields to select different file types, to select or specify a file, to display information about existing file, and to select between different save options. Fig. 81: Save panel File Format You can chose between ‘SPC Data’ and ‘SPC Setup’. The selection refers to different file types. With ‘SPC Data’ files are created which contain both measurement data and system parameters.
50 SPCM Software culated data or data loaded from another file. Except for special cases (see[2]) we recommend to use the ‘All used data sets’ option. Fig. 82: Save options Loading Setup and Measurement Data The ‘Load’ menu is shown in Fig. 83. It contains fields to select different file types, to specify a file, to display information about the file selected, and to select different load options. Fig. 83: Load panel File Format You can chose between ‘SPC Data’ and ‘SPC Setup’.
Predefined Setups 51 Block Info Activating a data block in the ‘Block Number in File’ field enables a ‘Block Info Button’. Clicking on this button opens a list that contains the device number of the SPC modules by which the data were recorded, the time and data of the recording, and all system parameters, see Fig. 84. At the end of the block information the minimum and maximum count rates of the corresponding measurement are shown (see Fig. 84, right).
52 SPCM Software Fig. 85: Editing the list of predefined setups To create your own predefined setups, first save a setup file of the system configuration you want to add the list. Use the ‘Save’ panel, option ‘setup’, as described under ‘Save’. Then add the file to the setup list as described above. You can also add an ‘.sdt’ file to the setup list. The .sdt file contains not only the system settings but also measurement data.
Importing FIFO Files 53 Importing FIFO Files Measurements in the absolute time modes deliver an .spc file that contains time-tag data, i.e. the micro time, the macro time, and the detector channel for each individual photon [2]. During a FIFO measurement normally decay curves, FCS curves, or photon counting histograms are calculated on-line. These data are saved in normal .sdt files.
54 SPCM Software The ‘Convert FIFO’ routine allows you to convert .spc files into different destination file types. The destination file type is specified in the ‘File Format’ field in the lower part of the Convert panel. The most frequently used conversion is into .sdt files of the TCSPC FIFO mode, see Fig. 87. Fig. 87: Conversion of .spc files into .sdt files of the FIFO mode. Left: Configuration of destination data. Right: Selection of the functions to be calculated and calculation parameters.
Format of Time-Tag Data Files 55 Format of Time-Tag Data Files In most of the operation modes the DPC-230 allows the user to record time-tag data of the individual photons. The format of the time-tag data files is described in this section. Time-tag data files consists of a sequence of 32 bit records. The first record is a descriptor that identifies the file as a DPC-230 time-tag file and contains the time-channel width of the recording. The subsequent records contains photon data.
56 SPCM Software loss of photons or any loss in photon information. Pre-processed data are identified by ‘RAW = 0’. The description given below relates to pre-processed data. Time per bin TPB[23:0] defines the time unit in which all subsequent photon data are expressed. TPB is given in femtoseonds. All times are expressed in multiples of TPB. Records of Photons The records following the descriptor are photon data. All detection events are recorded with their channel number and a 54 bit integer time stamp.
Format of Time-Tag Data Files 57 High-Time Record A record with bit 30 = 1 and bit 31 = 0 indicates that the higher part of the time has changed, and that a new high-part of the photon time has to be used starting from the previously recorded photon, see Table 5. In other words, both parts, TIME[53:24] of this and TIME[23:0] of the previous record, have to be used as a time tag.
Specification LVTTL Inputs No. of channels Input Voltage Threshold Min. Input Pulse Width Min. Pulse Distance Connectors 16 LVTTL 1.4 V 2 ns 5.
References 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. 22. 23. 24. 25. 26. 27. W. Becker, Advanced time-correlated single-photon counting techniques. Springer, Berlin, Heidelberg, New York, 2005 W. Becker, The bh TCSPC Handbook. 3rd. edition, Becker & Hickl GmbH (2006) Available on www.becker-hickl.com Becker & Hickl GmbH, DCC-100 detector control module, manual, www.becker-hickl.
62 28. 29. 30. 31. References R. Rigler, J. Widengreen, Utrasensitive detection of single molecules by fluorescence correlation spectroscopy, Bioscience 3, 180-183 (1990) P. Schwille, F.J. Meyer-Almes, R. Rigler, Dual-color fluorescence cross-correlation spectroscopy for multicomponent diffusional analysis in solution, Biophys. J. 72, 1878-1886 (1997) P. Schwille, U. Haupts, S. Maiti, W.W.W.
Index 2D FIDA 8 Absolute timing 2 Absolute timing mode 7 definition in the system parameters 45 Anti-bunching 31 combined with ps FCS 32 software setup 31 system parameters 31 A-PPI pulse inverter 22 Autocorrelation function 8 calculation from TDC data 9 normalisation 10 BDL-SMC picosecond diode laser 23, 25, 37 Beamsplitters, dichroic 27 Block Info 52 CFD inputs 20 Computer installation of DPC 14 memory size 14 operating system 14 requirements to 14 Convert FIFO files 54 Count rate count rate display 44 Cr
64 Index Inputs CFD inputs 20 configuration of 49 for PMT modules with TTL output 19 for PMT pulses 21 for SPADs 19, 21 LVTTL inputs 19 marker pulses 20 synchronisation to light sources 20, 22 Installation 14 device driver 16 DLL library 15 hardware 15 software 14 Intensity traces 7 online calculation 48 Load 52 data files 52 FIFO files 54 file formats 52 load options 53 predefined setups 40, 53 setup files 52 Luminescence decay in the µs range 25 laser control 25 optical and electronical setup 25 softwar
