Abstract: A phased array of flared amplifiers fed by phase adjusters and a power splitter produces a single high power beam when the flared amplifier sections are aligned and closely spaced. In one embodiment the array is excited by a DBR laser integrated into the same substrate as the flared amplifiers. In another embodiment the array is self-excited and forms a laser between an edge of the substrate common to the power splitter and an edge of the substrate common to the flared amplifier.

Abstract: A semiconductor laser includes a grating that is disposed at an angle to cavity reflectors to coherently diffract a beam of light along a path that is at least partially laterally directed within the cavity. The grating period and orientation are selected such that a specified wavelength of the light beam propagating along the path will resonate for light that impinges upon the end reflectors at normal incidence. By keeping the angle of incidence of the light beam upon the grating greater than about 45 degrees, reflectivity of the grating is maximized and the required grating period is larger thereby simplifying the fabrication of the grating.

Abstract: A semiconductor laser that includes at least one grating reflector with a grating period selected to diffract at a nonperpendicular angle within the plane of the laser waveguide. This allows dispersal of laser light, eliminating filamentary multimode operation of broad area lasers. In one embodiment, the grating reflector couples light between a single transverse mode waveguide portion of the optical cavity and a second, broad area, portion that is not collinear with the single mode waveguide. In another embodiment, the cavity favors a ring mode of oscillation. One or more grating reflectors form part of the feedback mechanism which forms a resonant optical cavity with noncollinear portions. Other reflectors in the feedback mechanism include facet reflectors which can be cleaved or ion milled, or semiconductor material refractive index boundaries. Laser embodiments with two or more grating reflectors can be independently tuned to provide a high rate of amplitude modulation.