Compact variable optical attenuator based on the W type waveguide

Abstract

We propose a compact variable optical attenuator (VOA) based on the W type five-layer symmetric slab waveguide. Simulation result shows that: for the attenuator based on GaAlAs/GaAs epitaxial layers, with a refractive index change of -0.01 in the current injection region of 1000 &mgr;m long (corresponding to injected current of about 80mA), an attenuation of more than 30dB is achieved. The attenuation range can be scaled to fit the requirements by varying the electrode length.