Experimental investigation of stability properties for a semiconductor laser with optical feedback

For applications in which a high degree of spectral purity and frequency stability is required, external cavity operation of a semiconductor laser represents an attractive possibility. The present investigation is concerned with some theoretical results regarding the stability of a semiconductor laser in an external cavity. The limits of stable operation for a semiconductor laser in an external cavity are calculated as a function of the feedback level and the phase of the reflected field. Experiments support the theoretical analysis and, in addition, allow a determination of the important R-parameter and the absolute level of optical feedback.