Polarisation effects in semiconductor optical amplifiers

Abstract

Optical switches based on SOAs are critical elements for the implementation of alloptical gating. The various wavelength conversion schemes are limited by their polarisation sensitivity. The polarisation sensitivity of SOAs, due to different gain and refractive indices in the TE and TM modes is well known and the resulting non-linear polarisation rotation can also be used for optical switching. Manufacturers characterize their devices in the continuous wave (CW) regime. However low gain anisotropy does not mean preservation of the input signal state of polarisation and for switching applications both CW and pulsed sources are used. The object of this thesis is to experimentally investigate the origins of the polarisation effects and how they affect the performance of SOAs, both in the continuous wave and dynamic regimes.