Twin-stripe injection laser with leaky-mode coupling

A new twin-stripe leaky-mode (TLM) injection laser has been demonstrated. The structure consists of two nominally 2-μm-wide stripes on 24-μm centers in a buried-heterostructure configuration (produced by mesa-etching a three-layer double heterostructure and burying with an AlGaAs layer). By adjusting the mole fraction of Al in the burying layer, a negative-index step is produced at the lateral stripe boundary. Thus a substantial fraction of laser power leaks into the low-loss waveguide region between the stripes, and strong stripe coupling is observed. The far field consists of two collimated (divergence ∼1°) beams characteristic of leaky-mode operation that are stable to pulsed drive current as high as 6Ith. Linear output characteristics are observed to powers greater than 150 mW.