US Patent 7567606 Strong distributed feedback semiconductor laser

The present invention relates to a strong distributed feedback semiconductor laser. More specifically, the invention implements a top optical waveguide (2) for semiconductor lasers having a surface metallic grating (5) making it possible to obtain a stable and controlled distributed feedback, using a simple and robust technology. In the inventive laser, which comprises an active area (1) having an effective refractive index (neff) in which a light wave is propagated with a wavelength (λ), the top waveguide (2) is made of a weakly-doped material and the periodic grating (5) depth (p) is