Pico Technical Support and Discussion Forum

Guest · Posted: Tue Sep 11, 2007 2:55 pm Post subject: Sample rate high enough?

Hello,

we want to make time resolved photoluminescence measurements of various dyes as a student experiment. For this we need a PC oscilloscope with a time resolution of about 0.5 ns to read the signal of a fast photo diode. The dye is excited by a pulsed laser with a repetition rate of 20 kHz and the luminescence has a decay time of several ns.

Since it is a student experiment, the price must not exceed 1000€. Is the 3204 oscilloscope suitable for this application?

Thanks

Jan Richters

ziko · Posted: Tue Sep 11, 2007 3:36 pm Post subject:

Hi and thank you for your post. To get 0.5ns a scope would be running at 2GS/s , the 3204 runs at 200MS/s so that is not achievable the best you can achieve would be 5ns in standard scope mode.

You say the a luminescence has a decay time of several ns is this why you want to sample at 0.5ns? If so then this is not possible. Our flagship model would at best achieve a time interval of 1ns (the 5203 or the 5204 that is).

Let me know if you require further assistance

Guest · Posted: Tue Sep 11, 2007 3:47 pm Post subject:

Thanks for your fast answer,

I was wondering wether the 3204 is suitable because your specifications say that the sampling rate of the 3204 for repetitive signals is 2.5 GS/s. By using a pulsed laser we will get a repetitive photoluminescence signal.

We need such a high sample rate, because the signal vanishes after a few ns and for fitting purpose we simply need some data points.

Thanks,
Jan Richters

ziko · Posted: Wed Sep 12, 2007 9:36 am Post subject:

Hi,

ETS only works if the signal you are measuring is stable and repetitive, since this mode works by building up the waveform from successive acquisitions.

Kind regards

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