Experimental demonstration of suppression of low-frequency fluctuations and stabilization of an external-cavity laser diode

We demonstrate experimentally all-optical stabilization of a single-mode la ser diode subject to external optical feedback operating in the low-frequen cy fluctuations (LFF) regime, by the technique of applying a second delayed optical feedback. We interpret our results as suppression of LFF through d estruction of the antimodes responsible for the LFF crises and stabilizatio n of the laser through creation of new maximum gain modes, in agreement wit h recent theoretical predictions. (C) 2000 Optical Society of America OCIS codes: 140.1450, 140.2020, 140.5960, 190.3100.