An optical modulator includes a light-emitting device and an upper electrode disposed on the light-emitting device. The upper electrode includes at least one first electrode portion for injecting a direct current to form a direct-current modulated segment, and a second electrode portion for injecting an alternating current to form an alternating-current modulated segment. The at least one first electrode portion and the second electrode portion are spaced apart from each other, and have a first length and a second length, respectively. The first length is greater than the second length. A method for manufacturing the optical modulator is also provided herein.

A method for forming a Bragg reflector includes after forming first trenches in the stack, which are intended to form structures of the distributed Bragg reflector, forming a sacrificial interlayer at least in the first trenches, depositing a second masking layer at least inside the first trenches, forming second trenches intended to form sidewalls of the laser, removing the second masking layer from inside the first trenches, removing said sacrificial interlayer so as to remove, by lift-off, residues of the second masking layer that remain inside the first trenches, and filling said first trenches with at least one metal material.

A vertical cavity surface emitting device includes a substrate, a first multilayer film reflecting mirror, a light-emitting structure layer with a light-emitting layer, and a second multilayer film reflecting mirror. The second multilayer film reflecting mirror constitutes a resonator between the first and second multilayer film reflecting mirrors. The second multilayer film reflecting mirror includes a first multilayer film, an intermediate film, and a second multilayer film. The first and second multilayer films have low refractive index films and high refractive index films that are alternately stacked. The intermediate film covers an upper surface of the first multilayer film and film has a translucency to a light emitted from the light-emitting layer. The second multilayer film partially covers an upper surface of the intermediate film. The intermediate film has a film thickness based on ½ of a wavelength inside the intermediate film of light emitted from the light-emitting layer.

A structure and method of formation of a buried heterostructure laser die with alignment aids wherein the alignment aids include lateral and vertical structures formed on the die. Lateral alignment aids are formed using a same mask layer as the ridge structure of the laser and provide fiducials that are formed in reference to the ridge structure. Vertical alignment aids, and vertical protrusions of the lateral alignment aids are formed using etch stop layers positioned in the buried heterostructure laser layer structure.

A semiconductor optical device includes an element structure layer that includes a mesa stripe extending in a first direction; an electrode film that covers at least an upper surface of the mesa stripe; an electrode pad portion that covers a part of a first region positioned in a second direction, intersecting the first direction, relative to the mesa stripe on an upper surface of the element structure layer and is electrically connected to the electrode film; a first dummy electrode that covers another part of the first region and is electrically insulated from the electrode film; and a second dummy electrode that covers at least a part of a second region positioned in a third direction, opposite to the second direction, relative to the mesa stripe on the upper surface of the element structure layer and is electrically insulated from the electrode film, wherein the first dummy electrode includes a first portion disposed in the first direction relative to the electrode pad portion and a second portion disposed in a fourth direction, opposite to the first direction, relative to the electrode pad portion.

Integrated-optics systems are presented in which an optically active device is optically coupled with a silicon waveguide via a passive compound-semiconductor waveguide. In a first region, the passive waveguide and the optically active device collectively define a composite waveguide structure, where the optically active device functions as the central ridge portion of a rib-waveguide structure. The optically active device is configured to control the vertical position of an optical mode in the composite waveguide along its length such that the optical mode is optically coupled into the passive waveguide with low loss. The passive waveguide and the silicon waveguide collectively define a vertical coupler in a second region, where the passive and silicon waveguides are configured to control the distribution of the optical mode along the length of the coupler, thereby enabling the entire mode to transition between the passive and silicon waveguides with low loss.

A manufacturing method of a device for generating terahertz radiation includes forming a distributed feedback laser epitaxy module; etching the distribution feedback laser epitaxy module corresponding to a first window to a predetermined depth; forming an indium gallium arsenide epitaxy layer above the distributed feedback laser epitaxy module corresponding to the first window; etching out the indium gallium arsenide epitaxy layer corresponding to a second window to expose the distributed feedback epitaxy module corresponding to the second window; forming a first electrode, a grating, and an antenna above an upper surface of the distributed feedback laser epitaxy module, an upper surface of the indium gallium arsenide epitaxy layer, and the distributed feedback laser epitaxy module corresponding to the second window, respectively; forming a second electrode above a lower surface of the distributed feedback laser epitaxy module; and forming two metal wires between the grating and the antenna.

Integrated-optics systems are presented in which an optically active device is optically coupled with a silicon waveguide via a passive compound-semiconductor waveguide. In a first region, the passive waveguide and the optically active device collectively define a composite waveguide structure, where the optically active device functions as the central ridge portion of a rib-waveguide structure. The optically active device is configured to control the vertical position of an optical mode in the composite waveguide along its length such that the optical mode is optically coupled into the passive waveguide with low loss. The passive waveguide and the silicon waveguide collectively define a vertical coupler in a second region, where the passive and silicon waveguides are configured to control the distribution of the optical mode along the length of the coupler, thereby enabling the entire mode to transition between the passive and silicon waveguides with low loss.

A semiconductor laser device of the present disclosure includes: a first-conductivity-type cladding layer, a first-conductivity-type-side optical guide layer, an active layer, a second-conductivity-type-side optical guide layer, a second-conductivity-type cladding layer, and a second-conductivity-type contact layer laminated above a semiconductor substrate; a resonator having a front end surface and a rear end surface; and a ridge region for guiding a laser beam between the front and rear end surfaces. The ridge region is composed of a ridge inner region in which an effective refractive index is n.sub.a.sup.i, and ridge outer regions which are provided on both sides of the ridge inner region and in which an effective refractive index is n.sub.a.sup.o, the ridge outer regions having current non-injection structures. A ridge outer region width W.sub.o is greater than a distance from a lower end of each current non-injection structure to the active layer.

An exemplary embodiment of the present invention relates to a method of fabricating at least one radiation emitter comprising the steps of depositing an etch stop layer on a top side of a substrate; depositing a layer stack on the etch stop layer, said layer stack comprising a first contact layer, a first reflector, an active region, a second reflector, and a second contact layer; locally removing the layer stack and the etch stop layer, and thereby forming at least one mesa, said at least one mesa comprising an unremoved section of the etch stop layer and a layered pillar which forms a vertical cavity laser structure based on the unremoved layer stack inside the at least one mesa; depositing a protection material on the top side of the substrate and thereby embedding the entire mesa in the protection material wherein the backside of the substrate remains unprotected; removing the substrate by applying at least one etching chemical that is capable of etching the substrate but incapable or less capable of etching the etch stop layer and the protection material; and removing the etch stop layer and thereby exposing the first contact layer of the at least one layered pillar.