Problem of Spike Elimination in Lasers

We have investigated theoretically and experimentally the conditions under which spiking in the laser output can be completely suppressed. It is predicted that a nonlinear absorber in the cavity producing greater loss at the higher power levels, and vice versa, should be highly effective. Experimental work was carried out with a single‐mode traveling‐wave laser, since in this case the predictions can be most easily checked. Instead of using a nonlinear absorber, a Kerr cell controlled by a feedback circuit was used. It was found, in agreement with theory, that the time delay between the build‐up of the electromagnetic energy in the cavity and the corrective action of the Kerr cell is a rather important parameter. Spike suppression can only be obtained when this time delay is short as compared to the duration of one oscillation pulse.