Negative differentiated optical injection of semiconductor lasers

Abstract

In this thesis, we present a new technique of semiconductor modulation that maintains simplicity of design and overcomes many deficiencies of current direct modulation technologies. This technique of negative differentiated optical injection locking, makes it possible to equal or improve the Q factor and reduce the chirp penalty of a directly modulated laser source. Using this new structure we stabilize the dielectric properties of the slave laser, beyond the performance of standard optical injection locking, by reducing the refractive index excursion in the active layer and minimizing optical frequency chirp. This enables more reliable bandwidth efficient communication without compromising linearity or demanding prohibitive control complexity. We contrast this technique with direct, standard injection locking, electro absorption and Mach-Zehnder modulators at various speeds and find that our particular technique demonstrates desirable trade-offs between performance, control flexibility and simplicity.