System for reducing pulse-to-pulse energy variation in a pulsed laser

Abstract

A system and method for reducing pulse-to-pulse energy and peak power variation in various types of pulsed lasers, and in Q-switched lasers in particular. The system of invention has a laser cavity with a lasing medium pumped by a pumping device for delivering to the medium a pumping energy E.sub.pump. The system further includes a detection device and circuitry for determining the pulse magnitudes M.sub.i of laser pulses i, such as peak pulse amplitudes A.sub.i, pulse energies E.sub.i, pulse widths W.sub.i or other pulse metrics. According to the method of invention, a feedback mechanism which is in communication with the pumping device ensures pulse-to-pulse stability by increasing the pumping energy E.sub.pump when pulse magnitude M.sub.i of laser pulse i exceeds a mean pulse magnitude [M] and decreasing the pumping energy E.sub.pump when M.sub.i is less than [M]. Alternatively, the feedback mechanism is in communication with the switching device which controls that variable loss factor of the Q-switch. Pulse-to-pulse peak and energy stability is achieved by decreasing the variable loss factor when M.sub.i of pulse i exceeds the mean [M] and increasing the variable loss factor when M.sub.i of laser pulse i is less than [M].