cw high-power single-mode operation of constricted double-heterojunction AlGaAs lasers with a large optical cavity

Abstract

A new type of constricted double-heterojunction (CDH) injection laser is presented: a single-mode laser with a large optical cavity (CDH-LOC) and leaky lateral waveguide. Single-mode cw operation (spatially and longitudinally) is achieved in a large lasing spot (1.7×6.5 μm) up to 40 mW output power (one facet) and 2.5 times above threshold. cw thresholds as low as 75 mA and external quantum efficiencies as high as 35% from one facet are obtained for diodes with reflectors on the back facet. The antiguiding nature of these devices is confirmed in the lateral far-field patterns. As opposed to positive-index lateral guiding structures, in CDH devices heating can be beneficial for single-mode selection at high powers.