Hello Forum,
My previous post went unanswered and so I've stumbled through on my own. My goal was to perform time correlated single photon spectroscopy. I'm using a 6321 X series DAQ card, a Perkin Elmer SPCM and a pulsed laser. I am exciting a sample with a laser and would like to obtain an accurate timestamp of the first photon detected after shutting down the laser. I would then repeat the measurement to build up a histogram from which I can obtain the lifetime of my sample (~1 micosecond).
As I understand it, the counter on X series cards can't be retriggered. My solution is to reset the counter with the falling edge of the signal that modulates the laser and then timestamp the first photon after that (attached). At the moment my program is giving me the timestamps of all the photons from the buffer, but I only want the first one. Is there a simple, elegant way to get just get the first element of the buffer on each shutdown without slowing down the data Acquisition loop?
Thanks in advance,
R
