Abstract

Injection of an external optical signal into a semiconductor laser can induce a variety of modified output characteristics. Depending on the frequency offset between master and slave lasers and the strength of the injected signal, stable and unstable injection looking and chaotic dynamics and multiwave mixing have been observed.^1,2 We have mapped the different kinds of dynamics observed experimentally in a conventional Fabry-Ferot laser diode under optical injection as a function of the detuning between the master and free-running slave lasers and the amplitude of the injected field.³ Stable injection locking, periodic oscillations at the injection-modified carrier-field resonance frequency, period-doubling and quadrupling, chaotic dynamics, four- wave mixing and multiwave mixing, subharmonic resonances at half the injection frequency offset, and mode hopping to other longitudinal modes are all observed under different injection conditions. For positive detuning the distinction between four-wave mixing and unstable oscillations at the modified resonance frequency and between subharmonic resonances and period-doubling oscillations can become blurred. At high injection levels, the region of stable injection-locked dynamics broadens and eventually dominates the whole range of injection-locked operation.

© 1996 Optical Society of America