Hi, I'm trying to use a polariser/pockels cell/analyser combination to make a fast optical switch. I have build a Marx bank to control the Pockels cell. The Marx bank delivers -3.5kV with a rise time of ~100ns (could go faster but don't need it to and due to design constraints have left it at this rise rate). This is the required voltage to operate the cell but it does not appear to rotate the polarisation much at all. The Pockels cell has been taken out of a very powerful femto-second laser as has a brown 'burn' mark which I think is only on one of the faces and does not extend into the crystal itself, though I can't be sure. I've been trying to get this system to work for some time and I'm beginning to wonder if the crystal itself is beyond usable, but I don't know enough about these crystals to be sure. I do know they're quite sensitive though, having only a 2% duty cycle. Can anyone tell me how I might determine if the crystal needs re-conditioning, or if I should just keep at it with optical alignment and electronics adjustments?