Shutters Pockels cell

Intense nanosecond pulses (Ins = 10 9s) can be produced by Q-switching. A shutter is placed between the laser rod and one of the mirrors, thus inhibiting lasing. If the shutter is suddenly opened, the excitation is dumped in one huge burst. One type of shutter is the electro-optic Pockels cell (KH2P04 crystal with a high applied potential). 

There is another way to obtain giant laser pulses of a few ns duration, known as active Q-switching. The shutter is an electro-optical cell which is triggered at some preset time after the pump flash. These electro-optical shutters are Kerr cells or Pockels cells. 

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