Provided is a surface emitting quantum cascade laser, including: semiconductor layers other than a laser active layer and the laser active layer; and a square-lattice or rectangular-lattice photonic crystal on the laser active layer, wherein a unit lattice of the square-lattice or rectangular-lattice photonic crystal is made of a composition A, and a composition B having a refractive index different from a refractive index of the composition A, and wherein the composition A is a compound semiconductor composition or metal composition, the composition B is a compound semiconductor composition, and the unit lattice of the square-lattice or rectangular-lattice photonic crystal has the following structure: a columnar structure body having a pentagonal bottom face and being made of the composition B is provided in a central part of the columnar structure body having the square or rectangular bottom face and being made of the composition A.

A light-emitting element includes a mesa structure in which a first compound semiconductor layer of a first conductivity type, an active layer, and a second compound semiconductor layer of a second conductivity type are disposed in that order, wherein at least one of the first compound semiconductor layer and the second compound semiconductor layer has a current constriction region surrounded by an insulation region extending inward from a sidewall portion of the mesa structure; a wall structure disposed so as to surround the mesa structure; at least one bridge structure connecting the mesa structure and the wall structure, the wall structure and the bridge structure each having the same layer structure as the portion of the mesa structure in which the insulation region is provided; a first electrode; and a second electrode disposed on a top face of the wall structure.

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 μm, 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 includes: plural light-emitting units; a driving unit that drives the light-emitting units by supplying a current to the light-emitting units; and a switching unit that is provided on a side opposite to a side where the driving unit is provided relative to the plural light-emitting units and switches light emission of the plural light-emitting units.

A surface-emitting laser includes a lower DBR layer, a cavity layer, and an upper DBR layer that are stacked in this order on top of a substrate, wherein the lower DBR layer has a first DBR layer, a contact layer, and a second DBR layer that are stacked in this order on top of the substrate, wherein the first DBR layer and the second DBR layer each include a plurality of first layers and a plurality of second layers that are alternately stacked, wherein the first layers and the second layers are each a semiconductor layer including aluminum, wherein a composition ratio of the aluminum of each first layer is lower than a composition ratio of the aluminum of each second layer, and wherein the second DBR layer includes 12 or more and 20 or fewer pairs of the first layers and the second layers.

The present embodiment relates to a single semiconductor light-emitting element including a plurality of light-emitting portions each of which is capable of generating light of a desired beam projection pattern and a method for manufacturing the semiconductor light-emitting element. In the semiconductor light-emitting element, an active layer and a phase modulation layer are formed on a common substrate layer, and the phase modulation layer includes at least a plurality of phase modulation regions arranged along the common substrate layer. The plurality of phase modulation regions are obtained by separating the phase modulation layer into a plurality of places after manufacturing the phase modulation layer, and as a result, the semiconductor light-emitting element provided with a plurality of light-emitting portions that have been accurately aligned can be obtained through a simple manufacturing process as compared with the related art.

A light emitting element (10A) of the present disclosure includes: a stacked structure (20) in which a first compound semiconductor layer (21) having a first surface (21a) and a second surface (21b), an active layer (23), and a second compound semiconductor layer (22) having a first surface (22a) and a second surface (22b) are stacked; a first light reflecting layer (41) formed on a first surface side of the first compound semiconductor layer (21) and having a convex shape in a direction away from the active layer (23); and a second light reflecting layer (42) formed on a second surface side of the second compound semiconductor layer (22) and having a flat shape, in which a partition wall (24) extending in a stacking direction of the stacked structure (20) is formed so as to surround the first light reflecting layer (41).

An optical device of one embodiment outputs light in a short-wavelength range such as a visible range. The optical device includes a UC layer, first and second light-confinement layers, and a resonance mode forming layer. The UC layer contains an upconversion material receiving excitation light in a first wavelength range and outputting light in a second wavelength range. The first light-confinement layer has a characteristic of reflecting part of the second wavelength-range light. The second light-confinement layer has a characteristic of reflecting part of the second wavelength-range light and transmitting the remainder, and is disposed such that the UC layer locates between the first and second light-confinement layers. The resonance mode forming layer locates between the UC layer and the first or second light-confinement layer, includes a base layer and plural modified refractive index regions, and forms a resonance mode of the second wavelength-range light.

An edge-emitting semiconductor laser includes: a semiconductor substrate; a first cladding layer having a first refractive index and formed on the semiconductor substrate; an active layer formed on the first cladding layer and having a second refractive index higher than the first refractive index; a Bragg reflector formed on the active layer and in which low-refractive-index layers and high-refractive-index layers each having a thickness larger than λ/4n are alternately laid one on another where λ is an lasing wavelength and n is a refractive index of a medium; a light absorption layer formed on the Bragg reflector and having bandgap energy lower than that of the active layer; and a second cladding layer formed on the light absorption layer and having a third refractive index lower than the second refractive index.

The present disclosure relates to a diode laser having reduced beam divergence. Some implementations reduce a beam divergence in the far field by means of a deliberate modulation of the real refractive index of the diode laser. An area of the diode laser (e.g., the injection zone), may be structured with different materials having different refractive indices. In some implementations, the modulation of the refractive index makes it possible to excite a supermode, the field of which has the same phase (in-phase mode) under the contacts. Light, which propagates under the areas of a lower refractive index, obtains a phase shift of π after passing through the index-guiding trenches. Consequently, the in-phase mode is supported and the formation of the out-of-phase mode is prevented. Consequently, the laser field can, in this way, be stabilized even at high powers such that only a central beam lobe remains in the far field.