Abstract

Semiconductor injection lasers are ideal vehicles for studying complex dynamics and chaos in nonlinear optical systems. Moreover, in view of the extensive applications of these lasers to optical communication and data storage, it is essential to study their dynamic properties in detail. Most previous studies of modulated semiconductor lasers have addressed small-signal responses,¹ and more recently the effects of strong modulation on devices which exhibit spontaneous self-pulsations.² Here we consider the dynamic behavior of semiconductor lasers, which are well behaved in isolation, under large-signal modulation at gigahertz rates. Nonlinear rate equations, including a strong sinusoidal external modulation term, are solved numerically to obtain the optical mode spectra, relative intensity noise spectra, and output power times series, for various laser biasing and modulation conditions. Various frequency locking and mixing phenomena have been observed. For fixed dc bias at a given modulation frequency, the laser undergoes complex transitions from periodic to chaotic responses, as the modulation depth is increased. However, these transitions occur at modulation depths considerably lower than those predicted by the authors of Ref. ². Numerical and experimental results are discussed.

© 1989 Optical Society of America