Recent content by alanwake90

Thx for ur reply very much. I think they were using the photodetector(or a combination of photodetectors, the signal to lock-in is A-B, photodetector A - Photodetector B to cut the background at first)to collect the signal. I believe that nowadays the bandwide of photodetector is at GHz level at...

Thank u so much for ur reply, But I still don't get it, I saw some papers taking about measuring THz oscillation using the optical pump-probe method I mentioned, on coherent phonon dynamics, for example. and they said that the chopper is used to chopping the pump laser at kHz level.I don't think...

Hi guys~ I have a question about lock-in detection method that commonly used in optical spectroscopy experiments, for example, the optical pump-probe reflectivity exeperiments on some semiconductor surfaces, or kinda like that. Usually, the sinario is: you use laser pulses, divided as pump and...