Abstract: A semiconductor light source comprises superluminescent diodes (SLDs) disposed on a substrate having a facet, channels separating the SLDs, and a mode expander region. Each SLD has a diamond shaped active region such that the front and rear end of each SLD ends in a taper. The mode expander region is disposed on at least one side of the tapers of the SLDs and is tapered into a waveguide extending to said facet.

Abstract: A semiconductor diode laser with thermal sensor control comprises a heat sink, a diode-laser structure, and a thermal sensor thermally coupled to said diode-laser structure in a place where the temperature gradient across the semiconductor diode laser is close to zero.

Abstract: A superluminescent diode having emission layers which emit different wavelengths of light disposed side-by-side whereby light emitting in a first direction from an emission layer having a longer wavelength than an adjacent layer in the first direction is not absorbed. Thus, light of the different wavelengths is represented in an output spectra in the first direction at a point beyond the adjacent layer. A semiconductor optical amplifier is formed by creating a symmetrical structure in which the longest wavelength material is grown in the center and the shortest wavelength material is grown near the facets.