Semiconductor lasers with the light output through the diffraction grating on the surface of the waveguide layer

In AlAs-GaAs semiconductor heterojunction lasers, due to the interaction of the waveguide modes with a diffraction grating on the surface of the waveguide layer, output of coherent radiation has been obtained through the plane parallel to the layer. The angle of divergence of the radiation in this case was equal to 0.5° both with optical and injection pumping. The possibility of fabricating a new type of semiconductor laser with small radiation divergence has been proven experimentally.