OPTICALLY PUMPED TAPER-COUPLED GaAs-AlxGa1 - xAs LASER WITH A SECOND-ORDER BRAGG REFLECTOR.

Optically induced laser action has been achieved at room temperature with a structure consisting of a pumped double-heterostructure (DH) GaAs active layer taper coupled to a low-loss passive Al//xGa//1// minus //xAs waveguide incorporating a second-order Bragg-reflection grating which served as a feedback component. In terms of injection pumping, the lasing threshold is equivalent to approximately 8 kA/cm**2. In contrast to optically pumped conventional DH GaAs-AlGaAs lasers, the output has a spectral width reduced to 2 A, its wavelength is insensitive to the pumping geometry, and the lasing always occurs in time at the peak intensity of the pump. Additional relevant active and passive data are also given.