Abstract

External cavity effects in semiconductor lasers have long been of interest. Reflectivities as low as 10^-8 have been shown to impact laser diode performance. Although feedback from a conventional dielectric mirror has been well studied, phase conjugate feedback has only recently been examined. External cavity diode lasers formed with phase conjugate mirrors have demonstrated linewidth narrowing, frequency selection, frequency stability, and coherence collapse.^[1,2,3] In this paper we will compare the effects of the diffferent types of external cavities, noting that not all phase conjugation techniques are similar. Typically, the rate equations for these systems are truncated after one round trip in the cavity. We will develop multiple round trip models and examine the range of validity for both approaches.

© 1992 IQEC