Ridge Formation for AlGaAs GRINSCH Lasers by Cl₂ Reactive Ion Etching

Optical storage applications for AlGaAs power lasers require single mode laser operation and well-controlled beam divergence. For AlGaAs GRINSCH ridge lasers, these optical characteristics are sensitive to the precise ridge geometry of the laser. Directional reactive ion etching with Cl2 and in situ monitoring of the etch with highly attenuated laser interferometry provide the excellent process control required during formation of the ridge. This letter describes this process and presents results from lasers that were fabricated using this technique. © 1990 IEEE