A quantum cascade laser includes a laser structure having an output face for emitting laser light in a first direction; and a lens having an entrance surface and a convex surface, the entrance surface receiving the laser light from the output face, and the convex surface emitting the laser light after being condensed by the lens. The laser structure includes a semiconductor substrate and a mesa waveguide provided on a first region of a principal surface of the semiconductor substrate, the mesa waveguide extending in the first direction. The lens includes a semiconductor and is provided on a second region of the principal surface of the semiconductor substrate. The first region and the second region are arranged in the first direction.

An optoelectronic device includes a semiconductor substrate and an optically-active structure, including epitaxial layers defining a lower distributed Bragg-reflector (DBR) stack, a quantum well structure with P- and N-doped layers disposed respectively on opposing sides of the quantum well structure, and an upper DBR stack. Electrodes are coupled to apply a bias voltage between the P- and N-doped layers. Control circuitry, disposed on the substrate, is configured to apply a forward bias voltage between the electrodes so as to cause the optically-active structure to emit an optical pulse through the upper DBR stack, and then to reverse the bias voltage between the electrodes so as to cause the optically-active structure to output an electrical pulse to the control circuitry in response to incidence of one or more of the photons, due to reflection of the optical pulse, on the quantum well structure through the upper DBR stack.

A light emission device includes: a plurality of semiconductor light-emitting elements; an optical element configured to collimate light emitted from each of the plurality of semiconductor light-emitting elements and output a plurality of collimated beams; a converging portion having an aspheric surface configured to converge the plurality of collimated beams; and a wavelength-converting portion including a transmissive region and a reflective region that surrounds the transmissive region, the transmissive region including a light-incident surface at which the plurality of collimated beams enter, wherein the transmissive region includes a phosphor adapted to be excited by the plurality of collimated beams that have been converged by the converging portion.

An optical device includes a first substrate, having first and second surfaces, and a second substrate having a third surface. The first substrate includes: a laser unit, having an active layer and emitting light into the first substrate from the active layer; a reflecting mirror, having a plane obliquely intersecting an optical axis of light emitted from the laser unit, and being formed on the first surface so as to reflect the light toward the second surface; and a convex lens, being formed in a region on the second surface, the region including an optical axis of the light reflected by the reflecting mirror. The second substrate is provided with a grating coupler and an optical waveguide on the third surface, the optical waveguide having light incident on the grating coupler propagating therethrough.

A vertical cavity surface emitting laser (VCSEL) may include a substrate layer, epitaxial layers on the substrate layer, and angled reflectors configured to receive an optical beam emitted toward a bottom surface of the VCSEL and redirect the optical beam through an exit window in a top surface of the VCSEL. In some implementations, the angled reflectors may be formed in the substrate layer. Additionally, or alternatively, the VCSEL may include molded optics, where the molded optics include the angled reflectors. In some implementations, the exit window may include an integrated lens.

A surface-emitting laser according to an embodiment of the present disclosure includes a current constriction region having an opening and formed by impurities injected into a laminate from side of a second semiconductor layer; and a first DBR layer on side of a first semiconductor layer and a second DBR layer on the side of the second semiconductor layer having the laminate interposed therebetween at a position facing the opening. At the opening, an opening diameter close to the first DBR layer is larger than an opening diameter close to the second DBR layer.

Top emitting vertical cavity surface emitting lasers (VCSELs) are described with various top side optical gratings, etched into and/or fabricated over the VCSELs, to configure optical emission properties to suite a wide range of applications. Top side gratings are configured for spanning one or multiple emitters in any desired alignment/misalignment, using a wide range of refractive index materials and arrangements, levels of dimensionality (1D, 2D or 3D), forms of chirping of the grating, various grating periods, transmissive/reflective properties and in-plane coupling, ranges of diffractive orders, different relative amplitudes of transmitted and reflected orders, different polarizations, different levels of collimation, different levels of divergence, different diffraction and reflection, different beam diffusion, fixed or varied rotation of optical output, and far field engineering of the optical output.

A light-emitting element includes: a laminated structure body 20 which is formed from a GaN-based compound semiconductor and in which a first compound semiconductor layer 21 including a first surface 21a and a second surface 21b that is opposed to the first surface 21a, an active layer 23 that faces the second surface 21b of the first compound semiconductor layer 21, and a second compound semiconductor layer 22 including a first surface 22a that faces the active layer 23 and a second surface 22b that is opposed to the first surface 22a are laminated; a first light reflection layer 41 that is provided on the first surface 21a side of the first compound semiconductor layer 21; and a second light reflection layer 42 that is provided on the second surface 22b side of the second compound semiconductor layer 22. The first light reflection layer 41 includes a concave mirror portion 43, and the second light reflection layer 42 has a flat shape.

A light emitting element according to the present disclosure includes a first light reflecting layer 41, a laminated structure 20, and a second light reflecting layer 42 laminated to each other. The laminated structure 20 includes a first compound semiconductor layer 21, a light emitting layer 23, and a second compound semiconductor layer 22 laminated to each other from a side of the first light reflecting layer. Light from the laminated structure 20 is emitted to an outside via the first light reflecting layer 41 or the second light reflecting layer 42. The first light reflecting layer 41 has a structure in which at least two types of thin films 41A and 41B are alternately laminated to each other in plural numbers. A film thickness modulating layer 80 is provided between the laminated structure 20 and the first light reflecting layer 41.

A quantum cascade laser includes a laser structure having an output face for emitting laser light in a first direction; and a lens having an entrance surface and a convex surface, the entrance surface receiving the laser light from the output face, and the convex surface emitting the laser light after being condensed by the lens. The laser structure includes a semiconductor substrate and a mesa waveguide provided on a first region of a principal surface of the semiconductor substrate, the mesa waveguide extending in the first direction. The lens includes a semiconductor and is provided on a second region of the principal surface of the semiconductor substrate. The first region and the second region are arranged in the first direction.