Abstract: A semiconductor laser comprising a substrate having a plurality of closely spaced channels in the surface thereof with mesas separating the channels to form a channelled region in the surface of the substrate. A first cladding layer overlies the surface of the substrate and the channels and has a surface layer over the channelled region which is not coplanar with the surface of this layer over the surrounding substrate. A cavity region comprising a guide layer and an active layer overlies the first cladding layer and a second cladding layer overlies the active layer. The active layer and guide layer taper in thickness in the lateral direction.

Abstract: A laser comprises a semiconductor body having a pair of end faces and including an active region comprising adjacent active and guide layers which is spaced a distance from the end face and a passive region comprising adjacent non-absorbing guide and mode control layers which extends between the active region and the end face. The combination of the guide and mode control layers provides a weak positive index waveguide in the lateral direction thereby providing lateral mode control in the passive region between the active region and the end face.

Abstract: A semiconductor laser comprising a substrate having a plurality of closely spaced channels in the surface thereof with mesas separating the channels to form a channelled region in the surface of the substrate. A first cladding layer overlies the surface of the substrate and the channels and has a surface layer over the channelled region which is not coplanar with the surface of this layer over the surrounding substrate. A cavity region comprising a guide layer and an active layer overlies the first cladding layer and a second cladding layer overlies the active layer. The active layer and guide layer taper in thickness in the lateral direction.

Abstract: A phase-locked laser array including a plurality of closely spaced channels in the surface of the substrate with lands therebetween with the laser oscillation occurring in a cavity region over each of the channels. A broad-area electrical contact provides uniform electrical current flow to each of the lasing regions. The individual oscillators are coupled by the overlap of their evanescent optical fields. The invention also includes a method of fabricating this array which includes the steps of forming a plurality of corrugations in the surface of a substrate, forming a solution having a super-saturated growth condition for planar and concave surfaces and an under-saturated growth condition for convex surfaces, contacting the corrugated surface to the solution thereby partially melting the convex portions of the surface and forming planar lands between the concave portions of the corrugations.

Abstract: A constricted heterostructure laser in which the active layer does not extend to an emitting facet. The light from the active layer is coupled into an underlying guide layer which provides lateral guidance of the laser beam to the emitting facet. The shape of the output laser beam in both the lateral and transverse directions may be varied by varying the shape of the guide layer in that portion of the laser where the active layer does not overlie the guide layer.

Abstract: A semiconductor laser having an active layer which has a non-zero thickness in a region adjacent to at least one of the mirror facets which is less than that of the remainder of the active layer in the longitudinal direction. In the region adjacent to the mirror facet the laser light propagates primarily in a non-absorbing guide layer adjacent to the active layer thus, reducing optical absorption and heat generation at the mirror facet.

Abstract: A semiconductor laser wherein the major surface of a substrate having a pair of channels therein is misoriented from a member of the {100} family of crystallographic planes by a tilt angle between about 0.2.degree. and 1.5.degree.. The misorientation angle of the substrate surface with respect to the axis of the channels is between about 5.degree. and 45.degree..

Abstract: A semiconductor laser comprising a substrate with a pair of grooves in the surface thereof and a first confinement layer which overlies the surface of the substrate and has a terrace in its surface. An active layer overlies the surface of the first confinement layer and has a portion of maximum thickness and its recombination region over the concave portion of the terrace in the first confinement layer. A weak asymmetric positive index optical guide is thus formed which supports only the fundamental lateral optical mode.

Abstract: The invention is a semiconductor laser which includes a substrate with a pair of substantially parallel grooves in a surface thereof with a mesa therebetween where the height of the surface of the mesa above the bottom of the grooves is different than the height of the major surface of the substrate above the bottom of the grooves. Layers deposited on this substrate exhibit an increased taper in thickness in the lateral direction.

Abstract: The invention is an improved buried heterostructure laser wherein the improvement comprises a cladding layer which is interposed between the mesa and the burying region and has a refractive index less than that of the burying region and the effective refractive index of the fundamental transverse mode. The discrimination against higher order modes of propagation provided by the structure permits the use of a wider active layer and thus a larger emitting area.

Abstract: A semiconductor laser having anti-guiding regions extending through the second confinement layer towards but not intersecting the active layer on both sides of the region of the confinement layer over a land between the grooves in the substrate. These anti-guiding regions serve to suppress higher order lateral optical modes by creating large radiative losses for these modes.

Abstract: The invention is a phase-locked array of CDH-LOC semiconductor injection lasers which has a single, coherent continuous wave output beam. Coupling between elements of the array can occur over long distances because the radiated light wave propagates primarily in the transparent guide layer of the array structure. The elements of the array are then thermally isolated from one another so that continuous wave operation can occur.

Abstract: The invention is an improved semiconductor laser diode which includes a substrate having a pair of substantially parallel grooves in a major surface thereof with a land therebetween, a first confinement layer overlying the major surface of the substrate and the surfaces of the grooves; a guide layer overlying the first confinement layer, an active layer overlying the guide layer and the second confinement layer overlying the active layer. The improvement is a guide layer which tapers in increasing thickness from that portion of the layer over the land and whose surface, contacting the active layer, is concave in shape, and an active layer which is thickest over the land between the grooves and tapers in decreasing thickness in the lateral direction. This structure provides a positive lateral waveguide index for light propagating in the active and guide layers resulting in a reduced threshold current for lasing action and a reduced spontaneous emission near threshold.

Abstract: A light emitting device comprises a substrate, a first confining layer overlying the substrate, an active layer overlying the first confining layer, a second confining layer overlying the active layer and a capping layer overlying the second confining layer. The improvement is the interposition of an absorber layer which absorbs light at the wavelength of the emission between the substrate and the first confining layer and a capping layer which absorbs light at the wavelength of the emission. The improved device exhibits an output beam which has a narrow angular intensity pattern in the plane perpendicular to the plane of the layers and to the end surfaces of the device.

Abstract: A body of a semiconductor material of a Group III-V compound or alloy of such compounds includes a substrate of one conductivity type with a pair of spaced, substantially parallel grooves in a surface thereof. Over the surface of the substrate and the grooves are, in sequence, a buffer epitaxial layer of the one conductivity type, a first confinement epitaxial layer of the one conductivity type, a guide epitaxial layer of the one conductivity type, an active epitaxial layer which is the active recombination layer, a second confinement epitaxial layer of the opposite conductivity type and a cap epitaxial layer of the opposite conductivity type. The epitaxial layers are of materials forming heterojunctions between the first confinement layer and the guide layer, and between the active layer and second confinement layer.

Abstract: A light emitting diode includes a substrate having a body of single crystalline semiconductor material, preferably a Group III-V compound or alloy thereof, on a surface of the substrate. The body includes a window layer directly on the substrate and one or more other layers on the window layer. The layers of the body are of appropriate conductivety types to form a recombination region in which light can be generated. The substrate has an opening therethrough to the window layer. The window layer is of a material which is substantially transparent to the light generated in the recombination region and is of a thickness, 15 to 30 microns, to provide rigidity to the diode.

Abstract: A body of semiconductor material of a Group III-V compound or alloy of such compounds includes a substrate of one conductivity type with a pair of spaced, substantially parallel, dove-tail shaped grooves in a surface thereof. Over the surface of the substrate and the grooves are, in sequence, a first epitaxial layer of the one conductivity type, a second epitaxial layer which is the active recombination layer, a third epitaxial layer of the opposite conductivity type and a fourth epitaxial layer of the opposite conductivity type. The first and third layers are of a material forming heterojunctions with the second active layer. The second active layer has a region of uniform thickness directly over the space between the grooves. A stripe contact is provided on the fourth layer directly over the region of minimum thickness of the second active layer.