Polarisation insensitive configuration of semiconductor laser amplifier

A new polarisation insensitive configuration of a semiconductor laser amplifier is presented. This configuration achieves polarisation insensitive gain by a bi-directional pass of the split polarised light waves through a laser amplifier. The experiments demonstrate a reduction of the gain difference from 5 dB to 0.1 dB while attaining a high fibre-to-fibre gain of 12 dB and a high saturation fibre output power of +6 dBm.