Abstract

Injection locking experiments with semiconductor lasers started in the early eighties. A lot of work was performed since then mainly dealing with locking range and stability, noise, modulation, chirp and linewidth reduction, sidemode injection locking, optical frequency conversion and micro-wave signal generation. However, there is a lack of quantitative comparison between experimental data and theory. The main reason for this relies on the fact that the experimental set-ups used in most former studies are based on the free-space propagation of light. This causes difficulties in controlling the exact amount of light injected into the slave laser cavity, because the spatial overlap between the optical mode in free-space and the slave laser waveguide is unknown. The experimental set-up presented in this paper allows to overcome this problem. The light generated by the master laser travels through an optical fibre before being injected into the cavity of the slave laser. Using the reciprocity principle, it is possible to control accurately the absolute light power injected from the master laser into the cavity of the slave laser once the power coupling coefficient between the slave waveguide mode and the fibre mode is determined. In addition, the polarisation can be fully controlled despite the birefringence of the optical fibre.

© 1998 IEEE