A single-transverse-mode GaAs laser device

A high radiance GaAs laser operating at room temperature, has been developed under contract to the National Aeronautics and Space Administration for use in an optical space navigation system. To achieve high radiance a single, 300 microns wide, GaAs diode is confined to the lowest-order transverse mode. This is accomplished by operating the laser diode with its mirror faces anti-reflection coated in an optical cavity in which the transverse mode is controlled by an aperture limiting slit. The asymmetry and small size of the active region and the very low impedance of the GaAs laser diode presented serious problems in designing a rugged and efficient device.