Photoconductive switch

Hi,

I am trying to produce voltage pulses with very short rise time (<15 ps), medium width (20 ns) and amplitudes up to 15 V. As a promising candidate I selected photoconductive switches and ultrafast photodiodes. However, I have limited knowledge about electronics at all and thus, even less knowledge about these devices. Do you think it is possible to produce pulses like that by applying a bias voltage to the switch/diode and send a laser pulse with approx. 20 ns width to the photosensitive area?

I already found photoconductive switches at Hamamatsu and Laser Quantum that might work. In particular, I am talking about the G4176-01 and the Tera-SED3, respectively. However, I cannot imagine how to connect these switches. For the Tera-SED3, one would have to use the ground as the output but how to deal with the grounds than without violating the impedance?

I appreciate any help, advise, new insights and ideas. Also, if you know another supplier of photoconductive switches or photodiodes that might work for my purposes, I would be very grateful if you share these with me.

The Hamamatsu device isn't able to generate more than a few ten mV output according to maximum ratings, the Laser Quantum device works as THz wave radiator and has no electrical output. Don't expect the bias input current port to have sufficient bandwidth.

Hi FvM,

thanks but I do not see where you get these information from. The Hamamatsu device would anyway be a test device, but the Laser Quantum device should work according to the costumer service. Why should there be a restriction in the bandwidth? Do you know any other way to produce such pulses or any other manufacturers of photoconductive switches?

For Hamamatsu, simply put in rated optical power, A/W value and 50 ohm output impedance. Related to the Laser Quantum device I'm actually guessing. If the vendor has measurements showing a respective current waveform, I would be glad about the correction. Unfortunately there's no specification of bias port impedance.