- #1
kicklop
- 6
- 2
Hello,
I have done an experiment with cutting out a pulse from continuous laser using Pockels cell. The setup is cw laser -> Pockels cell with crossed polariazers -> photodiode.
The photodiode is connected in reverse bias, a capacitor is connected parallel to photodiode.
If I put a half wave plate between the polarizers, continuous light goes on the photodiode. The photodiode measures voltage U.
Then I remove half wave plate and I cut out a 10 ns pulse from the same continuous light using Pockels cell. Now the photodiode measures a pulse, but its maximum is approximately 1/10*U.
I would expect the maximum of pulse signal to be the same as the signal from continuous light, because both pulses have the same intensity and photodiodes measure measure the intensity of light.
Can you explain, why the signals don't have the same maximum voltage output from photodiode, even though they have the same intensity?
I have done an experiment with cutting out a pulse from continuous laser using Pockels cell. The setup is cw laser -> Pockels cell with crossed polariazers -> photodiode.
The photodiode is connected in reverse bias, a capacitor is connected parallel to photodiode.
If I put a half wave plate between the polarizers, continuous light goes on the photodiode. The photodiode measures voltage U.
Then I remove half wave plate and I cut out a 10 ns pulse from the same continuous light using Pockels cell. Now the photodiode measures a pulse, but its maximum is approximately 1/10*U.
I would expect the maximum of pulse signal to be the same as the signal from continuous light, because both pulses have the same intensity and photodiodes measure measure the intensity of light.
Can you explain, why the signals don't have the same maximum voltage output from photodiode, even though they have the same intensity?