Intensity Pulsation Enhancement by Self-Focusing in Semiconductor Injection Lasers

Abstract

It is shown that self-focusing enhances intensity pulsations in injection lasers with little or no built-in refractive index waveguiding. The effect will promote onset of self-sustaind pulsations, when there is a saturable absorber in the laser cavity. Introduction of a lateral mode stabilizing refractive index waveguide structure reduces the enhancement effect and improves the direct modulation response characteristics, by reducing relaxation oscillations and making sustained pulsations less likely to occur.