Bistability of a CO2 laser with SF6 intracavity as an absorber: Transient effects

We investigated time-dependent effects related to the bistable operation of a CO₂ laser with an intracavity nonlinear absorber (SF₆). The response of the system to small perturbations was sensitively dependent on the operating laser line P(12)→P(30)] of the 10.6 μm band. The narrow bistable region forP(12), due to a very narrow hysteresis loop, can be effectively utilized for optical switching, because of its pronounced sensitivity to variations in operational parameters. The maximum admissable beam blocking time (intracavity) for spontaneous return to lasing was measured forP(16), for a range of absorber pressures. This τm is related to the relaxation time of the upper level in the absorber.