High-rate amplitude and frequency modulation of semiconductor lasers

The paper discusses the amplitude and frequency modulation characteristics of directly modulated semiconductor lasers, with emphasis on their application to the optical control of microwave semiconductor devices. Measurements of the amplitude and frequency modulation performance of a double-heterostructure GaAs/GaAlAs laser at frequencies between 2 and 3 GHz are presented. A simple theory of laser frequency modulation is developed, and is shown to be in good agreement with the experimental results. High-level modulation is shown to have a severe effect on the laser mode structure. Suggestions are made for optimising the high-frequency modulation performance of semiconductor lasers.