Q-switch of a continuously pumped CO2 laser with a scanning coupled-cavity Michelson mirror

We report on the possibility of Q-switching a continuously pumped CO2 laser using a scanning Michelson interferometer as an end mirror, instead of the habitual well-known strategies. This method, in addition to its simplicity, produces free tail relaxation pulses having duration of about 1.3 μs, which is comparable to what can be obtained when using a saturable absorber. A pulse repetition frequency as high as 90 kHz is obtained.