Patent ID: 8279901

Claim:
A variable repetition rate laser engine, comprising: an oscillator that generates and outputs a beam of femtosecond seed pulses; an integrated stretcher-compressor that stretches a duration of the seed pulses; and a Q-switched cavity dumped regenerative amplifier that amplifies an amplitude of selected stretched seed pulses to create amplified stretched pulses; wherein the stretcher-compressor compresses a duration of the amplified stretched pulses to output femtosecond laser pulses with the variable repetition rate, the configuration of the laser engine allowing the repetition rate to be varied while keeping the duration of the outputted laser pulses below 1,000 femtosecond; a number of optical elements of the laser engine is less than 75; and the amplifier comprises two end-mirrors defining a resonant cavity, and a switchable polarizer disposed between the end-mirrors configured to switch in less than 5 ns.