A measurement method for a vertical cavity surface emitting laser diode (VCSEL) and an epitaxial wafer test fixture are provided, especially the Fabry-Perot Etalon of the bottom-emitting VCSEL can be measured. When the Fabry-Perot Etalon of the bottom-emitting VCSEL is measured by a measurement apparatus, a light of the test light source of the measurement apparatus is incident from the substrate surface of the VCSEL epitaxial wafer such that the Fabry-Perot Etalon of the bottom-emitting VCSEL is acquired. Through the VCSEL epitaxial wafer test fixture, the bottom-emitting VCSEL can be directly measured by the existing measurement apparatus such that there is no need to change the optical design of the measurement apparatus, and it can prevent the VCSEL epitaxial wafer from being scratched or contaminated.

A surface-emitting laser element includes: a first guide layer including a photonic crystal layer that is formed on a c plane of a group-3 nitride semiconductor and includes air holes arranged with two-dimensional periodicity in a plane parallel to the photonic crystal layer, and an embedding layer that is formed on the photonic crystal layer and closes the air holes; an active layer formed on the first guide layer; and a second guide layer formed on the active layer, wherein an air hole set including at least a main air hole and a sub-air hole smaller in size than the main air hole is arranged at each square lattice point in the plane parallel to the photonic crystal layer, and wherein the main air hole has a regular-hexagonal prism shape, a long-hexagonal prism shape, or an elliptic cylindrical shape with a major axis parallel to a <11-20> axis.

A bottom-emitting multijunction VCSEL array includes a first reflector region, a multijunction active region, and a second reflector region. In one aspect, the multijunction VCSEL array is attached to a submount by flip-chip bonding. In another aspect, the multijunction VCSEL array further includes a contact layer formed between the first reflector region and the substrate. The multijunction VCSEL array is attached to a submount by flip-chip bonding.

A semiconductor device according to an embodiment may include a plurality of light emitting structures, a first electrode disposed around the plurality of light emitting structures, a second electrode disposed on an upper surface of the plurality of light emitting structures, a first bonding pad electrically connected to the first electrode, and a second bonding pad electrically connected to the second electrode. The plurality of light emitting structures may include a first light emitting structure that includes a first DBR layer of a first conductivity type, a first active layer disposed on the first DBR layer, and a second DBR layer of a second conductivity type disposed on the first active layer; and a second light emitting structure that includes a third DBR layer of the first conductivity type, a second active layer disposed on the third DBR layer, and a fourth DBR layer of the second conductivity type disposed on the second active layer. The first electrode may be electrically connected to the first DBR layer and the third DBR layer, and disposed between the first light emitting structure and the second light emitting structure. The second electrode may be electrically connected to the second DBR layer and the fourth DBR layer, and disposed on an upper surface of the second DBR layer and an upper surface of the fourth DBR layer.

There are provided a light emitting device capable of forming a light emitting element on a suitable substrate and a method of manufacturing the same.

A light emitting device according to the present disclosure includes: a first substrate; a plurality of light emitting elements that are provided on a first surface of the first substrate; and a second substrate that is provided on a second surface of the first substrate opposite to the first surface.

Provided is a vertical cavity surface emitting laser diode (VCSEL) with a small divergence angle. The VCSEL includes a multi-layer structure on a substrate. The multi-layer structure includes an active region and current confinement layers. Each of the current confinement layers has an optical aperture (OA). When the area of the OA of the current confinement layer outside the active region is larger than the areas of the OAs of the current confinement layers inside the active region, such that the VCSEL has a small divergence angle in the short pulse mode.

A columnar portion is formed by etching parts of an active layer and a first reflective layer. In this etching process, the columnar portion is formed by etching the first reflective layer to a position of a semiconductor layer. For example, it is etched to a thickness of approximately 3 μm.

A light source includes a substrate with a first surface and an opposite second surface. An epitaxial layer is positioned on the first surface of the substrate. The light source also includes at least one light generator in the epitaxial layer positioned such that an optical signal transmitted thereby is directed toward the substrate. A diffuser is positioned on the second surface of the substrate, and at least one monitor photodetector is positioned in the epitaxial layer in an arrangement configured to receive a portion of the optical signal which is reflected by the diffuser. In one form, the light generator may include a vertical cavity surface emitting laser (VCSEL).

An analysis device includes a substrate including a first surface, and a second surface positioned at a side opposite to the first surface; a light source part located at the first surface of the substrate, the light source part including a quantum cascade laser; a light detector located at the first surface of the substrate; and a wiring part located at the first surface of the substrate, the wiring part being electrically connected with the light source part and the light detector.

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.