Pulse stretching in a Q-switched Nd:YAG laser

Stretching of
Q
-switched Nd:YAG laser pulses has been achieved by rapidly varying the resonator output coupling during the pulse duration, using a Pockels cell driven by a high-voltage planar triode. An analytical solution for the temporal variation of loss, inversion, and photon density has been found. Flat laser pulses up to 600 ns duration and energy extraction efficiency close to 100 percent have been demonstrated experimentally.