Period-doubling route to chaos in a semiconductor laser with weak optical feedback

Abstract

We report experimental and theoretical observations of a period-doubling route to chaos in a semiconductor laser with optical feedback. Increasing the feedback produces a quasiperiodic route to chaos, manifested as a catastrophic increase in the laser linewidth. Under certain conditions, frequency locking occurs in preference to quasiperiodicity, and then period doubling appears. Both phenomena are explained as interactions between the external cavity modes and the laser relaxation oscillations.