The influence of external frequency shifted feedback on a DFB semiconductor laser

To investigate the possibility of optical isolation of a semiconductor laser using acoustooptic interaction, the influence of frequency shifted feedback on a DFB laser was studied experimentally. The isolation concept is based on a frequency shift of the laserlight by means of an acoustooptic Bragg deflection. This concept offers the opportunity of optical integration when Surface Acoustic Waves are used. In the experiments, a clear difference in laser performance between regular feedback and frequency shifted feedback was observed.