Waveguide grating mirror for large-area semiconductor lasers.

We have fabricated and tested a waveguide grating mirror that uses anomalous reflection of light associated with excitation of waveguide modes. Sharp features are observed in the reflection spectra in both the wavelength and the angular domains. We confirm experimentally that, when the waveguide grating mirror is placed a short distance in front of a large-area semiconductor laser, it can control the emission spectrum. This demonstration opens a new approach to the design of very compact semiconductor lasers operating in the single-frequency-single-mode regime.