Rca Inc.

General Electric Company

Dan Botez

John C Connolly

Michael Ettenberg

Henry Kressel

Gregory H Olsen

Jerome K Butler

Donald E Ackley

Bruce F Bogner

A phase-locked semiconductor laser array having a plurality of lasing regions includes phase-shifting means on the emitting surface thereof through which laser light is emitted. The phase-shifting means provide a phase shift for those laser beams passing therethrough so that the phases of all the emitted laser beams are substantially the same. The phase-shifting means include a coating on the emitting surface which has a spatially varying thickness in the lateral direction.

Phase-locked laser array with phase-shifting surface coating

A phase-locked laser array comprises a substrate with two spaced-apart pluralities of channels extending towards different reflecting surfaces of the array. The axes of symmetry of the channels of one plurality are offset from the axes of symmetry of the channels of the second plurality. Coupling of light propagating in the optical waveguides over one plurality of channels into the waveguides over the second plurality of channels induces a zero phase difference between the laser oscillations of adjacent channels.

Phase-locked laser array

A phase-locked laser array comprises a body of semiconductor material having means for defining a plurality of substantially parallel lasing zones which are spaced an effective distance apart so that the modes of the adjacent lasing zones are phase-locked to one another. One of the array electrodes comprises a plurality of electrical contacts to the body between the lasing zones. These contacts provide an enhanced current density profile and thus an increase in the gain in the regions between the lasing zones so that zero degree phase-shift operation between adjacent lasing zones is achievable.

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. The invention also includes a method of fabricating this laser which includes the steps of forming a plurality of corrugations in the surface of the 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 corrugations and forming mesas therebetween. Growth over the corrugations is delayed thereby providing a planar surface of the first layer over a central portion of the channelled region which is non-planar with respect to the surface of the layer over the remainder of the substrate. The trough thus formed by the delayed growth over the channelled region provides a curved surface upon which the remaining layers of the laser are then sequentially deposited.

Method of making a double heterostructure laser

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.

Semiconductor laser having a non-absorbing passive region with beam

Double heterostructure laser

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. Growth over the lands is delayed thereby providing a planar surface of the first layer upon which the remaining layers are then sequentially deposited.

Method of making a laser array

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..

Semiconductor laser having high manufacturing yield

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.

Semiconductor laser with non-absorbing mirror facet

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.

Semiconductor laser with reduced absorption at a mirror facet

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.

Terraced heterostructure semiconductor laser

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.

Constricted double heterostructure semiconductor laser

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.

W-Guide buried heterostructure laser

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.

High power semiconductor laser

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.

Growing community of inventors

Mount Holly, NJ, United States of America

Dan Botez