A novel, monolithically integrated mid-IR optical phased array (OPA) structure which eliminates the wafer bonding process to achieve highly efficient surface emitting optical beam steering in two dimensions is disclosed. Since solar energy is about 15-20 times smaller than that at 1.55 um, mid-IR is more favorable for the atmospheric transmission due to lower solar radiance backgrounds. For the beam steering, thermo-optic phase shifting is used for azimuthal plane beam steering and laser wavelength tuning is used for elevation plane beam steering. The OPA structure disclosed comprises a wavelength- tunable a QCL, a 1×32 splitter, thermo-optic phase-shifters, and sub-wavelength grating emitters. The disclosed OPA provides a low-cost, low-loss, low-power consumption, robust, small footprint, apparatus that may be used with expendable UAV swarms. A LiDAR may be created by monolithically integrating a QCD with the apparatus. Other embodiments are described and claimed.

A light-emitting device according to an embodiment of the present disclosure includes: a semiconductor stack in which a first light reflection layer configured by an arsenic-based semiconductor layer including carbon as an impurity, an active layer, and a second light reflection layer are stacked; a first buffer layer provided on the first light reflection layer side of the semiconductor stack, having one face that faces the semiconductor stack and another face that is on an opposite side of the one face, and configured by a phosphorus-based semiconductor layer; and a second buffer layer provided at least between the first light reflection layer and the first buffer layer, and configured by an arsenic-based semiconductor layer including zinc or magnesium as an impurity.

A semiconductor laser including a waveguide having a core, a confinement layer to bury the core, and a metallization layer. The core includes an active core region. The confinement layer surrounds the core and includes a first confinement layer between the core and the semiconductor substrate below the core, a second confinement layer above the core, and a third confinement layer to either or both sides of the core. The metallization layer is located above the confinement layers and include a first metallization layer and a second metallization layer. The first metallization layer is in direct contact with the second confinement layer and the third confinement layer, while the second metallization layer is disposed above the first layer. The first metallization layer is tuned to have a plasmon resonance corresponding to a higher order mode with high loss.

An optical semiconductor device includes an active layer having a plurality of quantum dot layers. The plurality of quantum dot layers includes at least one quantum dot player doped with a p-type impurity. Further, the plurality of quantum dot layers includes at least two quantum dot layers having different emission wavelengths and different p-type impurity concentrations.

A semiconductor laser device includes a first conductivity type cladding layer having a refractive index n.sub.c1, a first conductivity type side optical guide layer, an active layer, a second conductivity type side optical guide layer, and a second conductivity type cladding layer of n.sub.c2 laminated in order on a first conductivity type semiconductor substrate, wherein an oscillation wavelength is λ, a first conductivity type low refractive index layer of n.sub.1 lower than n.sub.c1 having a thickness of d.sub.1 is provided between the first conductivity type side optical guide layer and the first conductivity type cladding layer, a second conductivity type low refractive index layer of n.sub.2 lower than n.sub.c2 having a thickness of d.sub.2 is provided between the second conductivity type side optical guide layer and the second conductivity type cladding layer, and a condition of a normalization frequency v.sub.2>v.sub.1 is satisfied.

A semiconductor light-emitting module according to the present embodiment includes a plurality of semiconductor light-emitting elements each outputting light of a desired beam projection pattern; and a support substrate holding the plurality of semiconductor light-emitting elements. Each of the plurality of semiconductor light-emitting elements includes a phase modulation layer configured to form a target beam projection pattern in a target beam projection region. The plurality of semiconductor light-emitting elements include first and second semiconductor light-emitting elements that are different in terms of at least any of a beam projection direction, the target beam projection pattern, and a light emission wavelength.

A quantum-cascade laser element includes: an embedding layer including a first portion formed on a side surface of a ridge portion, and a second portion extending from an edge portion of the first portion along a width direction of a semiconductor substrate; and a metal layer formed at least on a top surface of the ridge portion and on the first portion. A surface of the first portion has a first inclined surface inclined with respect to the side surface to go away from the side surface as going away from the semiconductor substrate, and a second inclined surface located opposite to the semiconductor substrate with respect to the first inclined surface and inclined with respect to a center line to approach the center line as going away from the semiconductor substrate. The metal layer extends over the first inclined surface and the second inclined surface.

Provided are a vertical-cavity surface-emitting laser, a manufacturing method, a distance measuring device, and an electronic device. The vertical-cavity surface-emitting laser includes a lower electrode, a substrate, a lower Bragg reflector, an active area, a current limiting layer, an upper Bragg reflector, a protective layer, and an upper electrode. The upper electrode includes at least two sub-electrodes, the at least two sub-electrodes are electrically connected, and the at least two sub-electrodes define one or more light-exiting windows. Each sub-electrode is provided with a corresponding light-exiting window so that the luminous power is increased. Each sub-electrode defines the light-exiting window, and a plurality of sub-electrodes are electrically connected so that the distribution uniformity of the light spots is increased, and the quality of the laser beam is improved.

An optical device includes a first reflector; a second reflector; an elastic support unit supporting the second reflector; a piezoelectric element on the elastic support unit; a light emitter configured to emit light having an oscillation wavelength; and circuitry configured to output a signal to apply drive voltage to the piezoelectric element to elastically deform the elastic support unit. The deformation of the elastic support unit changes a distance between the first reflector and the second reflector to change the oscillation wavelength of the light emitted from the light emitter.

A two-dimensional photonic-crystal laser formed by sandwiching, between a first electrode and a second electrode, a layered body including an active layer and a two-dimensional photonic-crystal layer in which modified refractive index areas having a refractive index different from a refractive index of a plate-shaped base body are periodically arranged two-dimensionally on the base body. The first electrode is divided into a plurality of partial electrodes, and the second electrode is a frame-shaped electrode including a frame-shaped portion made of a conductor, the second electrode having a window portion which is a space inside the frame-shaped portion being arranged to face a region enclosing a plurality of the partial electrodes. A lens provided on the side opposite to the layered body of the second electrode in a manner covering the entire window portion is included.