Abstract: A compact semiconductor laser light source providing short wavelength (ultraviolet, blue or green) coherent light by means of frequency doubling of red or infrared light from a high power diode heterostructure. The high power diode heterostructure is a MOPA device having a single mode laser oscillator followed by a multimode, preferably flared, optical power amplifier. A tunable configuration having an external rear reflector grating could also be used. A lens could be integrated with the MOPA to laterally collimate the light before it is emitted. Straight or curved, surface emitting gratings could also be incorporated. An astigmatism-correcting lens system having at least one cylindrical lens surface is disposed in the path of the output from the MOPA to provide a beam with substantially equal lateral and transverse beam width dimensions and beam divergence angles. A nonlinear optical crystal or waveguide is placed in the path of the astigmatism-free symmetrized beam to double the frequency of the light.

Abstract: An optical amplifier with at least one high reflectivity facet oriented at a nonperpendicular angle to the amplifier's waveguide to couple light vertically through a top or bottom surface of the amplifier. Angled facets could be at just one end of the waveguide or at both ends of the waveguide. In the latter case, the facets can be approximately parallel to or perpendicular to each other for respective coupling to opposite or same sides of the amplifier. Multiple amplifiers can be formed end-to-and with v-grooves defining the angled facets or can be formed side-by-side with parallel waveguides. Waveguides can also branch to form a 1:2, 1:4 or 2:2 optical signal multiplier or optical switch depending on whether just one or all of the waveguide branches are electrically pumped. Fibers are coupled to the amplifier receiving and emitting surfaces. Angling the fiber end with respect to the surface prevents reflections from feeding back into the amplifier waveguide.

Abstract: An optical crossbar switch matrix for use in switching optical signals from a first set of optical fibers to a second set of optical fibers, in any order, which is characterized by having a matrix of rows and columns of diffraction gratings formed in a semiconductor heterostructure. Each grating is independently biased with either a forward or reverse bias voltage to switch the grating between a reflective state and a transmissive state. The gratings are oriented at an angle relative to the rows and columns so that when the Bragg condition for the light received from an optical film is met, a portion of the light is diffracted from the row in which it is propagating into a column toward another optical fiber. The heterostructure may include optical amplifiers to restore the optical signal to its original power level. Beam expanding, collimating and focussing optics may also be integrated into the heterostructure.