  We present a simple technique to produce active Q-switching in various types
of fiber amplifiers by active integration of an electrostatic actuated
deformable metallic micro-mirror. The optical MEMS (MOEMS) device acts as one
of the laser cavity reflectors and, at the same time, as switching/ modulator
element. We aim to obtain laser systems emitting short, high-power pulses and
having variable repetition rate. The electro-mechanical behavior of membrane
(bridge-type) was simulated by using electrostatic and modal 3D finite element
analysis (FEA). The results of the simulations fit well with the experimental
mechanical, electrical and thermal measurements of the components. In order to
decrease the sensitiveness to fiber-mirror alignment we are developing novel
optical devices based on stressed-metal cantilever-type geometry that allow
deflections up to 50 $\mu$m with increased reflectivity discrimination during
actuation.
