10
TIME STAMPING
Figure 19:
Block diagram for retrieving timestamps as an array
, see example
timestamparray.vi
.
www.qutools.com
quTAU/quPSI Manual V4.0 Page 29
Page 1: ...www qutools com info qutools com quTAU quPSI Manual V4 0 April 5 2016...
Page 2: ...ware Packages 8 4 4 Linux Support 9 5 Windows Installation 9 6 Firmware Update 9 7 Software 11 7 1 Concept 11 7 2 Daisy 12 7 3 quTAU GUI 13 7 4 Command Line Interface 13 7 5 Using the quTAU with your...
Page 3: ...Array 28 11 Histograms 30 11 1 Start Stop Histograms 30 11 2 Start Multistop Histograms Lifetime Measurements 34 11 3 Correlation Measurements HBT 38 12 Simulation and Testing Demo Mode 43 12 1 quTAU...
Page 4: ...file a settings dialog can be opened and additional information can be displayed The tabs 2 allow access to the different features of the device Please note the status bar 3 at the bottom showing add...
Page 5: ...dex html You can also find descriptions and examples for the most common tasks in this manual Working LabViewTM Examples like the one shown in Figure 2 are included in the userlib labviewXX examples f...
Page 6: ...are already integrated in the quTAU H model The key features of the quTAU device are 8 channels High timing resolution bin size 81 ps High event rates Coincidence counting integrated USB2 0 interface...
Page 7: ...ion ns Min 5 5 Input Impedance LV TTL 50 5000 Max event rates Mevents s 1ch counting 10 8ch counting 25 8ch time tags 3 Software Delay ns Min 50 Max 50 Figure 3 Hardware concept of the quTAU An ASIC c...
Page 8: ...ing width of time bins in a time difference histogram when using an odd number of bins for histogram binning Instead of a gaussian distribution the histogramm shows a comb structure due to the differe...
Page 9: ...e device if done incorrectly Do so only when it s advised by the manufacturer In that case please read and follow these instructions carefully Figure 5 The Firmware Update Utility NHFlash is ready to...
Page 10: ...tisfactory please press Flash The green LED should start flashing until it is finished At the end of the process the LED should be green again and the text close to it should read Update complete Make...
Page 11: ...I all applications are using the DLL tdcbase dll to communicate with the device driver 7 1 Concept The quTAU software concept is depicted in Figure 6 The device is connected via USB2 0 so the first pi...
Page 12: ...shown in Figure 7 the different features are simply accessed by clicking on the different tabs Double clicking a tab decouples it from the main window making it possible to view multiple tabs at once...
Page 13: ...an be saved to a file a settings dialog can be opened and additional information can be displayed The tabs 2 allow access to the different features of the device A status bar 3 at the bottom shows add...
Page 14: ...b doc index html Additionally there will be examples of how to combine the functions to achieve a certain task To visualize this simplified LabVIEWTM block diagrams will be used Please remember that t...
Page 15: ...tion was established and the DLL automatically switches to demo mode Necessary functions for the device initialization tdcbase h int TDC init int deviceId Additional functions related to the device in...
Page 16: ...lated to the device DE initialization tdchbt h void TDC releaseHbtFunction TDC HbtFunction fct tdclifetime h void TDC releaseLftFunction TDC LftFunction fct Table 3 Examples Device Deinitialization La...
Page 17: ...selection per channel channel delay per channel Trigger level necessary threshold voltage to trigger an event Termination switches the termination of the input channels between 50 and 5 k Edge select...
Page 18: ...he channel input settings can be changed via the controls in the highlighted area Please note that appearance of this window may change depending on the used hardware here a quTAU H is used 8 1 2 quTA...
Page 19: ...t TDC getSignalConditioning Int32 channel Bln32 on Bln32 edge Bln32 term double threshold int TDC configureSyncDivider Int32 divider Bln32 reconstruct int TDC getSyncDivider Int32 divider Bln32 recons...
Page 20: ...serlib labviewXX examples configure IO vi C Example userlib src example 1 3 5 c Figure 12 Digital Input configuration see example configure IO vi Please note that the logic level settings are set per...
Page 21: ...e unit Bins Two or more detection events will be counted as a coincident event if the difference of their time stamps is less or equal than the specified time window 9 3 Realizations Count rates can b...
Page 22: ...G Figure 13 Coincidence Counters Tab of the Daisy Parameters can be set at the top data are displayed as a bar plot and additionally as a trend graph for a selected channel www qutools com quTAU quPSI...
Page 23: ...f the quTAU GUI Data are displayed in the graph on the left hand side parameters can be set on the right hand side 1 Additionally all count rates are also displayed numerically besides the plot legend...
Page 24: ...s countrate plot vi When polled periodically the second argument update indicates the number of data updates since the last poll The timebase for all rates is set by TDC setExposureTime and the coinci...
Page 25: ...nary Since the 64 bits of timing information are more than are used internally they will never overflow The internal time will overflow after roughly 67 6 days see Section 4 2 10 1 3 Binary File 5 byt...
Page 26: ...h the Daisy GUI Select the Time Diffs tab 1 then use the Save Time Tags area 2 Click on the folder symbol to select a file location and name and start recording by clicking the red record button The L...
Page 27: ...ee Figure 18 Figure 18 The writing time stamps status window You can see the file name the current recording time and file size and the chosen maximum time and file size To stop recording time stamps...
Page 28: ...const Int8 channels Int32 count int TDC readTimestamps const char filename TDC FileFormat format 10 4 Retrieving Timestamps as an Array Table 8 Examples Retrieving Timestamps as an array LabView Examp...
Page 29: ...10 TIME STAMPING Figure 19 Block diagram for retrieving timestamps as an array see example timestamparray vi www qutools com quTAU quPSI Manual V4 0 Page 29...
Page 30: ...rences for the different histogram types For the A A Start Stop histogram the time differences x2 x1 x6 x2 x8 x6 and x9 x8 would be recorded In the A B case it would be x3 x2 x7 x6 and x10 x9 For the...
Page 31: ...Additionally you can change the number of merged HW bins in order to circumvent the TDC chip problem mentioned in 4 1 choose an even number and the histogram width The total integration time 2 is als...
Page 32: ...continuously generated The parameters of TDC getHistogram determine the channel combination to be retrieved Additionally an array with at least bincount entries has to be provided in the function call...
Page 33: ...11 HISTOGRAMS Figure 22 Block diagram for start stop histograms see example start stop vi www qutools com quTAU quPSI Manual V4 0 Page 33...
Page 34: ...f2 t I0 e t 0 1 e t 1 2 Kohlrausch Decay Function Stretched Exponential f3 t I0 e t 0 3 11 2 2 Realization in the quTAU GUI Lifetime Measurements can be obtained and analyzed in the quTAU GUI see Fig...
Page 35: ...stogram width In order to analyze the obtained data a fit to one of the three models described above can be chosen 2 The fit function will be displayed 3 Edit the start values 4 if the fit does not wo...
Page 36: ...ifetime Measurements tdcbase h Bln32 TDC checkFeatureLifeTime tdclifetime h int TDC enableLft Bln32 enable int TDC setLftParams Int32 binWidth Int32 binCount int TDC getLftParams Int32 binWidth Int32...
Page 37: ...Lifetime measurements see example lifetime vi The TDC analyzeLftFunction function is a convenient function to retrieve single values and the histogram array from the data set www qutools com quTAU qu...
Page 38: ...ry Brown and Twiss shown in Figure 25 It consists of two single photon detectors located at each output of a 50 50 beam splitter Time difference measurements of photon detections can then be used to a...
Page 39: ...Antibunching g 2 ab 1 e 0 a 7 Three Level System g 2 tl 1 p2 f c e 0 b 1 c e 0 a 8 Normalization Please note that the measured histogram data are normalized with a factor N R1R2TW 9 with countrates R...
Page 40: ...ed data a fit to one of the three models described above with the option to include detector jitter and an offset can be chosen 2 The fit function and the obtained parameters will be displayed 3 Edit...
Page 41: ...checkFeatureHbt tdchbt h int TDC enableHbt Bln32 enable int TDC setHbtParams Int32 binWidth Int32 binCount int TDC getHbtParams Int32 binWidth Int32 binCount int TDC setHbtDetectorParams double jitte...
Page 42: ...HBT measurements see example hbt measurement vi The TDC analyzeHbtFunction function is a convenient function to retrieve single values and the histogram array from the data set www qutools com quTAU q...
Page 43: ...Usage For simulation and testing events can be generated by the software as if they were pro duced by real signals There are several options generate timestamps Using the function TDC generateTimestam...
Page 44: ...e external sources Table 12 Channel Mapping of the quPSI device Please note that this only applies for read out timestamps and count rates but not for the input settings Source External Sync External...
