Feedback insensitive integrated semiconductor ring laser concept using weak intracavity isolation

摘要

External optical feedback can influence semi-conductor laser performance to a great extent. Strong optical isolators with reasonable insertion loss are not available in a photonic integrated circuit due to material incompatibilities, preventing the use of an isolator external to the laser cavity to suppress any feedback effects. In this work the feedback sensitivity of a semiconductor ring laser with an intra-cavity isolation of less than 10 dB is studied using a rate equation analysis. It is found that the relative intensity noise and linewidth are insensitive to feedback strengths over ?10 dB.