AlGaAs/GaAs VISIBLE RIDGE WAVEGUIDE LASER WITH MULTICAVITY STRUCTURE.

Ridge waveguide lasers of two different cavity configurations are described. One is a multisection ridge laser structure in which longitudinal mode selection due to the coupled-cavity effect was observed and single-frequency operation was achieved. Stable single-transverse-mode operation was ensured by the 5- mu m-wide central section, and the beam waist and power output were enlarged by the 10- mu m-wide outer sections. Output power of more than 13 mW under pulsed excitation was obtained. The second configuration is a shallow groove ridge laser in which the 5- mu m-wide shallow groove terminates slightly above the active region and provides an index perturbation that contributes to mode selection. All the lasers are designed to emit in the visible range between 7600 and 7900 angstrom. The shortest observed wavelength is 7570 angstrom and can be seen by the naked eye.