Efficient Pulse Stretching of Q-Switched Lasers

We present a new and simple technique for efficient stretching of Q-switched laser pulses using a novel ring resonator and a variable Pockels cell Q-switch driven by a simple circuit. The production of 10-mJ flat-topped Q-switched pulses with a duration that can be stretched by a factor of 4.5-1.8 mus without loss of pulse energy is demonstrated. We show that the pulse stretching agrees well with predictions of a numerical model.