All-optical intensity noise suppression for solid-state and semiconductor lasers

This paper will report on a new all-optical technique of relative intensity noise (RIN) suppression for solidstate and semiconductor lasers. The new scheme we have used is based on an unbalanced Mach-Zehnder interferometer (UMZI), which is able to cancel the intensity noise enhancement at relaxation resonance. Although the relaxation oscillations frequency and the level of the corresponding noise maximum are extremely different concerning solid-state microchip lasers and semiconductor laser diodes, the proposed passive noise suppression is well suited for both types of laser sources used in telecommunication. The UMZ fiber interferometer solution for solid-state lasers demonstrated hereunder was generalized and deployed in case of semiconductor lasers as well.