MEMS-based tunable single-passband microwave photonic filter

Abstract

Single-passband microwave photonic filters have significant advantages such as wide tuning range and high reconfigurability making them attractive photonic subsystems for modern telecommunication systems. However, implementation of such a reconfigurable subsystem requires compact, reliable and low cost tuning mechanism [1-3]. We report a novel Microelectromechanical Systems (MEMS)-based tunable single-passband microwave photonic filter that uses a chirped fiber Bragg grating as a dispersive element, instead of the conventional single mode optical fiber cable. The tunability is accomplished using a MEMS interferometer implemented by inserting a cleaved single mode fiber in front of a gold-platted micromirror fabricated by Deep Reactive Ion Etching (DRIE) on a Silicon On Insulator (SOI) wafer [4-6]. The filter is tuned by changing the length between the fiber end and the mirror (ΔL).