High gain and low polarization dependent 1.55-/spl mu/m semiconductor optical amplifier with a spot-size converter

Abstract

We have designed and fabricated a polarization independent spot-size convertor-semiconductor optical amplifier (SS-SOA) using a wide rectangular waveguide for ease of fabrication. The polarization dependence of the gain in the active region and that of the coupling efficiency in the SS regions on both sides of the device are compensated together by using a separate-confinement heterostructure (SCH) layer in the active region. The SS-SOA exhibits high-performance characteristics, such as low polarization dependence, high gain, efficient coupling to fiber, and uniform far-field-patterns.