Coupled-cavity waveguide reflectors suitable for use in high-Q reflective spectral filters, narrow-linewidth lasers, and the like, are presented. Coupled-cavity waveguide reflectors in accordance with the present disclosure comprise multiple waveguide segments arranged in a series, each segment including a tooth having relatively higher refractive index and a gap having relatively lower refractive index, where the lengths of the teeth and gaps are based on the position of their respective segments in the series. The lengths of the teeth and gaps are selected such that the reflectivity of the segments align at only a single wavelength, thereby enabling very narrow-linewidth operation.

Provided is a nitride semiconductor laser element which includes: a stacked structure including a plurality of semiconductor layers including a light emitting layer, the stacked structure including a pair of resonator end faces located on opposite ends; and a protective film including a dielectric body and disposed on at least one of the pair of resonator end faces. The protective film includes a first protective film (a first emission surface protective film), a second protective film (a second emission surface protective film), and a third protective film (a third emission surface protective film) disposed in stated order above the stacked structure. The first protective film is amorphous, the second protective film is crystalline, and the third protective film is amorphous.

A semiconductor laser diode is disclosed. In an embodiment a semiconductor laser diode includes a first resonator and a second resonator, the first and second resonators having parallel resonator directions along a longitudinal direction and being monolithically integrated into the semiconductor laser diode, wherein the first resonator includes at least a part of a semiconductor layer sequence having an active layer and an active region configured to be electrically pumped to generate a first light, wherein the longitudinal direction is parallel to a main extension plane of the active layer, and wherein the second resonator has an active region with a laser-active material configured to be optically pumped by at least a part of the first light to produce a second light which is partially emitted outwards from the second resonator.

An optical semiconductor device outputting a predetermined wavelength of laser light includes a quantum well active layer positioned between a p-type cladding layer and an n-type cladding layer in thickness direction. The optical semiconductor device includes a separate confinement heterostructure layer positioned between the quantum well active layer and the n-type cladding layer. The optical semiconductor device further includes an electric-field-distribution-control layer positioned between the separate confinement heterostructure layer and the n-type cladding layer and configured by at least two semiconductor layers having band gap energy greater than band gap energy of a barrier layer constituting the quantum well active layer. The quantum well active layer is doped with 0.3 to 1×10.sup.18/cm.sup.3 of n-type impurity.

To provide a light-emitting apparatus capable of shaping light from a plurality of light-emitting elements into light with a plurality of shapes and a manufacturing method thereof. A light-emitting apparatus according to the present disclosure, including: a substrate; a plurality of light-emitting elements which are provided on a side of a first surface of the substrate; and a plurality of first lenses which are provided on a side of a second surface of the substrate and on which light emitted from the plurality of light-emitting elements is incident, wherein the plurality of first lenses include at least two types of lenses among a concave lens, a convex lens, and a flat lens.

A vertical cavity light-emitting element includes a substrate, a first multilayer reflector, a semiconductor structure layer, an electrode layer, and a second multilayer reflector. The semiconductor structure layer includes a first semiconductor layer of a first conductivity type on the first multilayer reflector, a light-emitting layer on the first semiconductor layer, and a second semiconductor layer of a second conductivity type on the light-emitting layer. The electrode layer is on an upper surface of the semiconductor structure layer and is electrically in contact with the second semiconductor layer in one region of the upper surface. The second multilayer reflector covers the one region on the electrode layer and constitutes a resonator with the first multilayer reflector. The semiconductor structure layer has one recessed structure including one or a plurality of recessed portions passing through the light-emitting from the upper surface in a region surrounding the one region.

A semiconductor laser is provided with: an active layer that excites a transverse electric (TE) mode and a transverse magnetic (TM) mode of light and constitutes at least a part of a resonator guiding the TE mode and the TM mode of light; and a diffraction grating as a frequency difference setting structure that sets the difference in oscillation frequency between the TE mode and the TM mode of light higher than a relaxation-oscillation frequency.

A method and device for emitting electromagnetic radiation at high power using nonpolar or semipolar gallium containing substrates such as GaN, AlN, InN, InGaN, AlGaN, and AlInGaN, is provided. In various embodiments, the laser device includes plural laser emitters emitting green or blue laser light, integrated a substrate.

A semiconductor laser device includes an N-type cladding layer, an active layer, and a P-type cladding layer. The active layer includes a well layer, a P-side first barrier layer above the well layer, and a P-side second barrier layer above the P-side first barrier layer. The P-side second barrier layer has an AI composition ratio higher than an AI composition ratio of the P-side first barrier layer. The P-side second barrier layer has band gap energy greater than band gap energy of the P-side first barrier layer. The semiconductor laser device has an end face window structure in which band gap energy of a portion of the well layer in a vicinity of an end face that emits the laser light is greater than band gap energy of a central portion of the well layer in a resonator length direction.

An optical system comprising an optoelectronic device having a facet and a coating on the facet. The facet is configured to be in optical communication with at least a first optical medium during a first time period and a second optical medium during a second time period. The first optical medium has a first refractive index and the second optical medium has a second refractive index different from the first refractive index. The coating is configured to provide a first reflectance during the first time period for optical signals in a predetermined wavelength range and to provide a second reflectance during the second time period for optical signals in the predetermined wavelength range wherein the second reflectance is equal to the first reflectance within a negligible margin for optical signals having at least one wavelength in the predetermined wavelength range.