Q-switched fiber laser using a torsional micro-mirror

Micro-optical and micro-electro-mechanical technologies are merging to create a new and broader class of micro-opto-electro-mechanical (MOEM) devices. The goal of this paper is to study the functionality of a micro-mirror in a switchable opto-mechanical system. For that purpose, we have built a compact pulsed fiber laser with a torsional micro-mirror as switching element. The fiber laser is based on a 120 mm long Nd/sup 3+/ doped fiber. The cavity consists of a micro-mirror and a Bragg grating. The torsional micro-mirrors (50 /spl mu/m/spl times/70 /spl mu/m) are fabricated by polysilicon surface micro-machining. The fiber laser is spliced on a wavelength division multiplexing (WDM) coupler, allowing one to use the Bragg grating as output reflector, while pumping through it. With this configuration, we measured the laser threshold (3 mW) and the slope efficiency (19 %).