Abstract: A diode laser external lens cavity configuration having a stripe mirror with two thin parallel stripes placed in front of the two lobes of the arrays for far field output pattern. The configuration includes a diode laser array or broad area laser, a lens system, such as a graded-index lens, disposed in front of the laser's front light emitting facet and the stripe mirror disposed in front of the lens system at the focal plane of the lens. The two stripes are parallel to one another on opposite sides of and equidistant from a vertical reference plane through the lens' center axis. One stripe is highly reflective, while the other is effectively only partially reflective having either a lower stripe reflectivity or shorter length than the first stripe. Other embodiments include a third stripe spaced from and collinear with the second stripe to form an etalon, and a grating in the cavity.

Abstract: GaAs/AlGaAs heterostructure lasers containing indium in at least one layer other than or in addition to the active region. Embodiments are described in which indium added in low concentration to the cladding functions to match the lattice constants between the cladding and active layers, in which indium is added in high concentration to form strain layers that prevent defect migration therethrough and if proximate to the active region decrease transparency current and increase differential gain, in which indium is added uniformly to all layers to suppress defect formation, and in which indium is added to a cap layer to reduce metallization contact resistance.

Abstract: A diode laser of the type having an array of laser emitters in a Talbot cavity in which edge reflectors are added to enhance feedback to edgemost emitters. In one embodiment, a transparent slab with reflectively coated sides is present between the phase plane of the emitted light and the Talbot cavity reflector. The phase plne is defined by a lenticular array placed a focal length in front of the laser emitters. In another embodiment, the Talbot cavity reflector has an increased reflectivity toward its edges. In all embodiments the Talbot cavity reflector is preferably spaced a distance na.sup.2 /.lambda. from the phase plane, where n is a positive integer, a is separation between adjacent emitters and .lambda. is the wavelength of emitted light. An integrated embodiment has the array and cavity reflectors defined ina single semiconductor body divided into active and ransparent region. Side mirrors are etched into the semiconductor body.

Abstract: A method of making semiconductor laser arrays having an impurity disordered pattern of waveguides at least some of which are directly joined at branching junctions. The region near the branching junctions provides a phase boundary condition in which lightwaves propagating in adjacent waveguides are in phase. Using one impurity dose and one disordering depth in a first portion of the pattern and another in a second portion of the pattern provides a combination of strong and weak waveguiding with strong waveguides that eliminate evanescent coupling from occurring at least in the branching junction regions, and with weak guides near one or both end facets permitting evanescent coupling. The evanescent coupling between adjacent weak waveguides preserves the in phase relationship that was established in the Y-junction regions, resulting in a diffraction limited single lobe far field output.

Abstract: A quantum well heterostructure laser has low current density threshold and high T.sub.O values and includes a plurality of contiguous semiconductor layers formed on a substrate wherein one or more the layers form an active region capable of quantization of electron states. The active region is confined by a pair of outer superlattice regions which provide optical confinement and low thermal resistance while preventing the development of antiwaveguiding properties. Many configurations are shown to demonstrate the many forms that the overall laser structure can take and, in particular, the nature of the outer or inner cladding regions of different superlattice geometries and forms.

Abstract: A pyrotechnic ignition method in which a semiconductor laser bar or bars containing a number of independent laser array sources deliver optical power in a specified sequence through optical fibers to a set of pyrotechnic elements in order to initiate a sequence of pyrotechnic events, such as a fireworks display, building demolition, emergency ejection sequence, satellite launch, etc. A command signal is transmitted and received, typically by a remote station from the user. The signal is decoded to generate a set of electrical signals representing addresses of individual laser arrays on the laser bar. The laser arrays are activated in the desired sequence in response to the set of electrical signals and emit laser light. This light is transmitted along optical fibers coupled to the individual laser arrays and terminating in pyrotechnic elements. The pyrotechnic elements are ignited in response to optical power received from the optical fibers, typically by direct heating of a detonator.

Abstract: A window laser having at least one window region with a transparent waveguide layer optically coupled to an active region generating lightwaves. The waveguide layer is characterized by a broader guided transverse mode for the lightwaves than the active region and may have a thickness which is greater than the active region, a refractive index difference with respect to cladding layers which is less than a refractive index difference between the active region and the cladding layers, or both. The waveguide layer may be coupled to the active region via a transition region characterized by a gradual change in the guide mode width of the lightwaves, such as from a tapered increase in thickness of the waveguide layer in a direction away from the active region.

Abstract: The thermalization process is effectively slowed down by reducing the tunneling or communication probability between adjacent quantum wells of a MQW heterostructure laser to increase the number of allowable subbands in the wells and thereby correspondingly increase the range of wavelength tuning of such lasers. This increase of allowable subbands is accomplished by (A) either (1) spatially varying the elemental composition of the wells or barriers or both in order to spatially increase or decrease the energy band from well to well or (2) spatially varying the thickness of the wells or barriers or both in order to spatially increase or decrease the energy band from well to well, or (B) a combination of (1) and (2) of (A).

Abstract: A laser in which the central portion is provided with current pumping means consisting of an array of current confining stripe contacts to provide a multiple emitter active layer and the end sections of the laser are provided with transparent waveguides. The active layer of this laser can be abruptly stepped along the direction of light propagation, or provided with tapered end couplers, or in any other way made transparent, so that light escapes from the emitters of the active layer of the central portion of the laser into the transparent waveguides at the ends of the laser. The transparent waveguides are of a non-absorbing material of higher bandgap than the central active layer material, or of the same material but otherwise rendered transparent, so that the escaping light strikes the mirror facets and is reflected back, whereby a portion of the reflected light couples back into its emitter and provides the optical feedback for laser operation.

Abstract: A plurality of diode lasers is focussed onto a single region by arranging the diodes at equally spaced locations on a first arc. Each diode laser emits light in a slit-like pattern which is characterized by orthogonal axes. In a first group of cylindrical lenses, one associated with each diode laser, each lens has a refractive surface having an axis parallel to one of the emitting axes of the laser and refracts light to a focal region of defined dimensions. Each cylindrical lens is disposed along a second arc having a circular center common with the first arc. A second group of cylindrical lenses, one associated with each laser, is also disposed on a circular arc, concentric with the other arcs, but the second group has a refractive axis perpendicular to the first refractive axis. The second group of cylindrical lenses acts upon the second axis of the source image, focussing it to the common focal region. The first and second cylindrical lens groups may be combined into a toric surface within a single lens.

Abstract: An optical system producing bright light output for optical pumping, communications, illumination and the like in which one or more fiberoptic waveguides receive light from one or more diode lasers or diode laser bars and transmit the light to an output end where it is focused or collimated into a bright light image. The input end of the fiberoptic waveguide may be squashed into an elongated cross section so as to guide light emitted from an elongated light source such as a diode laser bar. The waveguides are preferably arranged at the output end into a tightly packed bundle where a lens or other optical means focuses or collimates the light. The bundle has a fused output end with a taper to a smaller output diameter, thereby producing a spatially uniform high power density light output. For diode laser bars much wider than 100 microns, a plurality of waveguides may be arranged in a line to receive the light, and then stacked at the output in a less elongated configuration.

Abstract: An optical system producing bright light output for optical pumping, communications, illumination and the like in which one or more fiberoptic waveguides receive light from one or more diode lasers or diode laser bars and transmit the light to an output end where it is focused or collimated into a bright light image. The input end of the fiberoptic waveguides may be squashed into an elongated cross section so as to guide light emitted from an elongated light source such as a diode laser bar. The waveguides are preferably arranged at the output end into a tightly packed bundle where a lens or other optical means focuses or collimates the light. For diode laser bars much wider than 100 microns, a plurality of waveguides may be arranged in a line to receive the light, and then stacked at the output in a less elongated configuration. In this manner, light from many diode lasers or laser bars may be coupled through the bundle into the end of solid state laser medium.

Abstract: Lasers and laser arrays having various optical elements, such as lenses, apertures, prisms, etalons and phase plates, integrated within the resonant optical cavity of the laser. The optical elements are created by introducing a lateral geometric contour in boundaries of refractive index changes thereby causing a change in shape of phase fronts of lightwaves propagating in the laser cavity in a manner analogous to optical elements. Boundaries may be defined between an active region and transparent window regions or may be formed in other layers with which lightwaves interact, such as the layers bounding the active region. Curved boundaries produce convergent or divergent lenses. Absorbing regions may bound window regions to produce apertures for lateral mode control. A periodic step shaped boundary can be used to shift the phase of lightwaves propagating in some laser array waveguides relative to lightwaves in others of the waveguides in order to cause beam emission of a desired supermode.

Abstract: A semiconductor laser array having a plurality of waveguides at least some of which are directly joined at Y-junctions. The region near the Y-junctions provides a phase boundary condition in which lightwaves propagating in adjacent waveguides are in phase. A combination of strong and weak waveguiding is provided, with strong waveguides that eliminate evanescent coupling from occuring at least in the Y-junction regions, and with weak guides near one or both end facets permitting evanescent coupling. The evanescent coupling between adjacent weak waveguides preserves the in phase relationship that was established in the Y-junction regions, resulting in a diffraction limited single lobe far field output. Alternatively, even without evanescent coupling, the modes can adjust their phases in the weak waveguides, where the propagation constant is less tightly specified by the geometry.

Abstract: A diode laser bar producing a linear array of laser beams without lateral superradiance. The laser bar has a double-heterostructure or quantum well structure. Etched channels in the substrate create lateral corrugations in the subsequently deposited layers including the active region. The corrugations alternate between offset groove and plateau regions in the lateral direction but are straight in the longitudinal light propagating direction. Any laterally propagating light is interrupted at steps, between groove and plateau regions, by deflection, scattering or transmission out of the active region. Interruption may also be achieved with a plurality of parallel etched grooves extending in the longitudinal direction. The grooves which cut through the active region present a semiconductor-air interface for reflection and/or scattering of laterally propagating light out of the active region.

Abstract: A laser having a combination of end and side pumping so as to produce high power pulsed output with little or no delay between side pump pulses and laser output pulses, with suppressed spiking due to gain switching, and with high modulation rates. An active medium, such as a solid state laser rod, in a resonant optical cavity is pumped by a first optical pump source directing radiant energy into an end of the active medium so as to encourage or establish lasing operation in a desired transverse cavity mode, such as the TEM.sub.00 mode. A second optical pump source directs additional radiant energy into a side of the active medium so as to amplify the intensity of the laser output in the desired mode.

Abstract: An optical system producing bright light output for optical pumping, communications, illumination and the like in which one or more fiberoptic waveguides receive light from one or more diode lasers or diode laser bars and transmit the light to an output end where it is focused or collimated into a bright light image. The input end of the fiberoptic waveguide may be squashed into an elongated cross section so as to guide light emitted from an elongated light source such as a diode laser bar. The waveguides are preferably arranged at the output end into a tightly packed bundle where a lens or other optical means focuses or collimates the light. For diode laser bars much wider than 100 microns, a plurality of waveguides may be arranged in a line to receive the light, and then stacked at the output in a less elongated configuration. In this manner, light from many diode lasers or laser bars may be coupled through the bundle into the end of solid state laser medium.

Abstract: A phased array laser having a laterally asymmetric variation in the gain or coupling of lasing elements of the array for emission in a single far field lobe. The lasing elements are confined by internal waveguide structuring, periodically spaced current confinement stripes, or by a hybrid of both waveguiding and current confinement. The widths, lengths, depths, or separations of the waveguides or stripes vary laterally across the array to affect the gain or coupling of the lasing elements. Alternate embodiments introduce lateral asymmetry in the active region or other layer thicknesses, doping, mirror facet reflectivities, A1 content of the layers, heat dissipation, or thicknesses of electrical contacts. The laterally asymmetric variations may be linear or nonlinear, monotonically increase from one edge to the other edge, or may be such that the relevant parameter is greatest or least in the center of the array.

Abstract: A semiconductor laser array having a plurality of sets of interconnecting waveguides, each joining two optical waveguides together at respective branching junctions. The array has a plurality of semiconductor layers disposed on a substrate, at least one of the layers forming an active region for light wave generation and propagation under lasing conditions. One or more structures, such as current confining channels, a channelled substrate and variable thickness active region define a plurality of adjacent optical emitting waveguides. The waveguides are coupled together in a coupling geometry which ensures that breaks or failures in one or more branches are bypassed, thereby maintaining in-phase laser array operation.

Abstract: A semiconductor laser array having a single lobe far field intensity pattern radiating normal to the laser's light emitting facet. The laser array has a plurality of semiconductor layers disposed over a substrate, at least one of the layers forming an active region for lightwave generation and propagation under lasing conditions. A plurality of adjacent spaced apart optical waveguides defined by waveguides and interconnecting waveguides directly couples lightwaves propagating in each waveguide into an adjacent waveguide. The waveguides are characterized by separations which are not equal at the light emitting facet but are selectively varied so that the sampling function has only a single central lobe. In the preferred embodiment, separations are greatest for edge located and smallest for centrally located waveguides. Interconnecting waveguides connect adjacent waveguides at respective Y-shaped junctions, the junctions being symmetric at least on the output side of the laser.