Integration of Micro-Electro-Mechanical Deformable Mirrors in Doped Fiber Amplifiers

TL;DR

This paper introduces a novel method for active Q-switching in fiber amplifiers using integrated electrostatically actuated deformable micro-mirrors, enabling short, high-power laser pulses with adjustable repetition rates.

Contribution

It presents a new integration technique of MEMS deformable mirrors into fiber lasers for improved pulse control and introduces stress-metal cantilever designs for better alignment tolerance.

Findings

Simulations match experimental mechanical, electrical, and thermal measurements.

Developed stressed-metal cantilever mirrors with up to 50 μm deflections.

Achieved variable repetition rate laser pulses.

Abstract

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.