Abstract: A planar, topology free, semiconductor quantum-well laser is described. The quantum-well active layer is formed and patterned in a specified region which is constrained on all sides by high bandgaps which are formed through the use of impurity-free diffusion techniques. After the impurity-free diffusion has taken place, an upper portion is then epitaxially deposited to complete the structure. High-power, single fundamental mode laser operation is achieved by funneling current into the constrained quantum-well active region, high bandgap regions in conjunction with low index of refraction in regions surrounding the active area. The structure is further designed to allow low beam divergence in the direction perpendicular to the semiconductor laser junction.

Abstract: A planar, topology free, semiconductor quantum-well laser is described. The quantum-well active layer is formed and patterned in a specified region which is constrained on all sides by high bandgaps which are formed through the use of impurity-free diffusion techniques. After the impurity-free diffusion has taken place, an upper portion is then epitaxially deposited to complete the structure. High-power, single fundamental mode laser operation is achieved by funneling current into the constrained quantum-well active region, high bandgap regions in conjunction with low index of refraction in regions surrounding the active area.The structure is further designed to allow low beam divergence in the direction perpendicular to the semiconductor laser junction.

Abstract: A semiconductor ridge waveguide laser having a high value of horizontal far-field wherein the laser structure includes a substrate, a first or lower cladding layer composed of a AlGaAs on the substrate, an acting layer on the lower cladding layer, and a second or upper cladding layer composed of AlGaAs on the active layer. The upper cladding layer includes a raised ridge portion formed by etching the upper cladding layer through a mask. A contact layer is disposed on top of the ridge portion. The aluminum mole concentration of the lower cladding layer is greater than the aluminum mole concentration of the upper cladding layer. This forces the optical mode towards the upper cladding layer and results in an increased lateral waveguide confinement that produces a high horizontal far-field.

Abstract: The process is particularly useful in the fabrication of GaAs quantum well (QW) laser diodes. Starting point is a ridge-patterned (100)-substrate (21), the crystal orientation of the sidewalls, e.g., (411A)-oriented, being different from that of the horizontal top. The sidewall facets thus have a lower Ga incorporation rate.In a molecular beam epitaxy (MBE) system, the lower AlGaAs cladding layer (22) is first grown, followed by the high-temperature growth of the active GaAs QW (23). Due to diffusion and desorption processes, the GaAs thickness at the sidewalls is smaller than on the horizontal top of the ridge. During a short growth interrupt, the GaAs completely desorbs from the sidewall facets. With the subsequent growth of the upper cladding layer (24), the QW becomes laterally embedded in higher bandgap material providing for lateral electric confinement.

Abstract: Apparatus and method for producing coherent blue-green-light radiation having a wavelength of essentially 490-500 nm. A diode laser, such as a strained-layer InGaAs/GaAs diode laser, provides a 980-1,000 nm beam, and a nonlinear crystal of KTP produces coherent radiation by noncritically phase-matched second-harmonic generation (SHG) of said beam. The beam preferably has a wavelength of essentially 994 nm for generating radiation having a wavelength of essentially 497 nm. The crystal is disposed within an optical resonator and the frequency of the laser is locked to that of the resonator. Alternatively, two diode lasers are oriented to provide orthogonally polarized beams each with a wavelength of 980-1,000 nm but within essentially 1 nm of each other, and the KTP crystal is oriented with its a- and c-axis parallel to the orthogonally polarized beams. The KTP crystal may have an associated optical waveguide along which the beam is propagated to enhance SHG efficiency.

Abstract: A GaAs/AlGaAs-transverse junction stripe (TJS) laser with p-n junction formation by crystal plane dependent doping is described. The laser structure includes a molecular beam epitaxy (MBE)-deposited hetero-structure comprising AlGaAs layers with an active GaAs layer sandwiched therebetween. These layers are grown on the patterned surface of a GaAs substrate which provides (100)-plane oriented planar ridges and grooves, the edges being (111A)-plane oriented. p-n homojunctions are formed in the GaAs layer at the intersections of the (111A) and (100) crystal planes. Ohmic contacts are provided for applying currents of at least the threshold level of the junctions. These TJS lasers can be used to form 1- or 2-dimensional arrays of phase-coupled lasers for providing high optical power output.