A method for manufacturing an optical semiconductor device having a ridge stripe configuration containing an active layer and current blocking layers which embed both sides of the ridge stripe configuration, comprises steps of forming a mask of an insulating film on a surface of a semiconductor layer containing an active layer, forming a ridge stripe configuration by etching a semiconductor layer using gas containing SiCl.sub.4, removing an oxide layer with regard to a Si based residue which is attached on a surface which is etched of the ridge stripe configuration which is formed and removing a Si based residue whose oxide layer is removed.

A laser resonator includes an active material, which amplifies light associated with an optical gain of the resonator, and passive materials disposed in proximity with the active material. The resonator oscillates over one or more optical modes, each of which corresponds to a particular spatial energy distribution and resonant frequency. Based on a characteristic of the passive materials, for the particular spatial energy distribution corresponding to at least one of the optical modes, a preponderant portion of optical energy is distributed apart from the active material. The passive materials may include a low loss material, which stores the preponderant optical energy portion distributed apart from the active material, and a buffer material disposed between the low loss material and the active material, which controls a ratio of the optical energy stored in the low loss material to a portion of the optical energy in the active material.

An embodiment semiconductor optical device includes an optical waveguide including a core, and an active layer extending in the waveguide direction of the optical waveguide for a predetermined distance and arranged in a state in which the active layer can be optically coupled to the core. The core and the active layer are arranged in contact with each other. The core is formed of a material with a refractive index of about 1.5 to 2.2, such as SiN, for example. In addition, the core is formed to a thickness at which a higher-order mode appears. The higher-order mode is an E.sub.12 mode, for example.

An embodiment semiconductor optical device includes an optical waveguide including a core, and an active layer extending in the waveguide direction of the optical waveguide for a predetermined distance and arranged in a state in which the active layer can be optically coupled to the core. The core and the active layer are arranged in contact with each other. The core is formed of a material with a refractive index of about 1.5 to 2.2, such as SiN, for example. In addition, the core is formed to a thickness at which a higher-order mode appears. The higher-order mode is an E.sub.12 mode, for example.

A semiconductor light emitting device includes a substrate, and an array including three or more light emitting elements which are aligned above and along a main surface of a substrate and each emit light. The light emitting elements each include a clad layer of a first conductivity type, an active layer containing In, and a clad layer of a second conductivity type disposed above the substrate sequentially from the substrate. Among the light emitting elements, the compositional ratio of In in the active layer is smaller in the light emitting element located in a central area in an alignment direction than that in the light emitting elements located in both end areas in the alignment direction.

A method of producing laser bars or semiconductor lasers includes providing a carrier composite to form a plurality of carriers for the laser bars or for the semiconductor lasers, providing a semiconductor body composite including a common substrate and a common semiconductor layer sequence grown thereon, forming a plurality of separation trenches through the common semiconductor layer sequence such that the semiconductor body composite is divided into a plurality of semiconductor bodies, applying the semiconductor body composite to the carrier composite such that the separation trenches face the carrier composite, thinning or removing the common substrate, and singulating the carrier composite into a plurality of carriers, wherein a plurality of semiconductor bodies are arranged on one of the carriers, and the semiconductor bodies arranged on one common carrier are laterally spaced apart from one another by the separation trenches.

Aspects for an on-chip or integrated Light Detection and Ranging (LiDAR) device are described herein. The aspects may include a semiconductor optical waveguide integrated in the LiDAR device. A receiving end of the semiconductor optical waveguide may receive a light beam from a light source. One or more beam splitters may be configured to split the light beam into two or more light beams. At least one semiconductor optical amplifier (SOA) may be integrated to amplify the power of the light beam or the split two or more light beams.

Aspects for an on-chip or integrated Light Detection and Ranging (LiDAR) device are described herein. The aspects may include a semiconductor optical waveguide integrated in the LiDAR device. A receiving end of the semiconductor optical waveguide may receive a light beam from a light source. One or more beam splitters may be configured to split the light beam into two or more light beams. At least one semiconductor optical amplifier (SOA) may be integrated to amplify the power of the light beam or the split two or more light beams.

Semiconductor laser architectures that provide weak index guiding of interband cascade lasers (ICLs) processed on a native III-V substrate and of ICLs grown on GaAs or integrated on GaAs by heterogeneous bonding. Weak index guiding of a ridge waveguide semiconductor laser can enhance the stability of lasing in the fundamental lateral mode, so as to allow a wider ridge to maintain stable single-lateral-mode operation.

Semiconductor laser architectures that provide weak index guiding of interband cascade lasers (ICLs) processed on a native III-V substrate and of ICLs grown on GaAs or integrated on GaAs by heterogeneous bonding. Weak index guiding of a ridge waveguide semiconductor laser can enhance the stability of lasing in the fundamental lateral mode, so as to allow a wider ridge to maintain stable single-lateral-mode operation.