An illumination system (200) includes an illumination device (202); an optical element (206) positioned to receive light (208) from the illumination device (202); a layer (210) of a transparent material disposed on the optical element (206) and positioned to receive light (208) from the illumination device (202); and an interlock circuit (220) configured to measure a resistivity of the layer (210) of transparent material and to control operation of the illumination device (202) based on the measured resistivity.

A wavelength filter includes a first filter circuit and a second filter circuit. The first filter circuit that has a passband that is obtained from a vernier effect by connecting, in series, a plurality of ring resonators each having a different transmission wavelength interval and that is within a gain band of an optical amplifier, and that passes, from the gain band, light at a selected wavelength and light that has a wavelength in a recursive mode and that is produced on a short wavelength side or a long wavelength side of the selected wavelength. The second filter circuit is connected to the first filter circuit in series and suppresses the light at the wavelength in the recursive mode from the light passing through the first filter circuit.

A laser module includes: a laser diode bar including a plurality of emitters configured to emit laser light from a front surface and leak light from a rear surface; a housing including a reflecting surface configured to surround a space together with the laser diode bar and reflect, toward the space, light leaked from the rear surface, in a scattering manner; and a detector configured to detect light reflected by the reflecting surface. A laser module includes: a laser diode bar including a plurality of emitters configured to emit laser light from a front surface and leak light from a rear surface; a condenser lens on which light leaked from rear surfaces of all of the plurality of emitters impinges; and a detector configured to detect light transmitted through the condenser lens.

A diffractive optical element (10) comprises a microstructure plane provided thereon with at least one microstructural pattern unit. The diffractive optical element (10) can receive a light beam emitted from a partitioned light source array (20) and project a light field on a target surface (OB), wherein the partitioned light source array (20) comprises a plurality of light source arrays (20-1, 20-2, ..., 20-n) spaced along a first direction, and the microstructural pattern unit is configured to be capable of diverging and light homogenization-modulating a light beam emitted from a light source in the plurality of light source arrays (20-1, 20-2, ..., 20-n) along the first direction such that light field regions projected by adjacent light source arrays (20-1, 20-2, ..., 20-n) on the target surface are adjoined or overlapped with each other in the first direction. In the embodiments of the invention, there are gaps between adjacent partitions. The light source partitions are lightened in turn. When each light source partition is lightened, only a region in the target light field corresponding to the partition is illuminated uniformly. Moreover, when all partitions are lightened together, the whole target light field is illuminated uniformly. There is no dark space caused by gaps between partitions, thereby realizing uniform illumination of partitions in the target light field.

To reduce the wiring inductance when establishing electrical connection between a semiconductor laser and a laser driver in a semiconductor laser driving apparatus. A semiconductor laser driving apparatus includes a substrate, a laser driver, and a semiconductor laser. The substrate incorporates the laser driver. The semiconductor laser is mounted on one surface of the substrate. Connection wiring electrically connects the laser driver and the semiconductor laser to each other with a wiring inductance of 0.5 nanohenries or less. A shield suppresses flow of electromagnetic waves to/from an outside of the semiconductor laser driving apparatus for at least one of the semiconductor laser and the laser driver.

An optical waveguide package includes a substrate, and an optical waveguide layer on an upper surface of the substrate. The optical waveguide layer includes a cladding and a core in the cladding. The cladding has at least one first recess having a bottom surface and a first inner wall surface surrounding the bottom surface. The first inner wall surface of the at least one first recess is inclined and has an upper side outward from a lower side.

A lighting device includes: a light-emitting element having multiple first light-emitting sections and multiple second light-emitting sections; a first optical member that causes multiple pieces of first light outputted from the multiple first light-emitting sections and multiple pieces of second light outputted from the multiple second light-emitting sections to be substantially collimated, and outputs the multiple pieces of first light and the multiple pieces of second light; and a second optical member that shapes beam shapes of the multiple pieces of first light, beam shapes of the multiple pieces of second light, or both the beam shapes of the multiple pieces of first light and the multiple pieces of second light, and outputs the multiple pieces of first light and the multiple pieces of second light in a manner that the beam shapes are different between the multiple pieces of first light and the multiple pieces of second light.

An addressable vertical cavity surface emitting laser (VCSEL) array may generate structured light in dot patterns. The VCSEL array includes a plurality of traces that control different groups of VCSELs, such that each group of VCSELs may be individually controlled. The VCSEL groups are arranged such that they emit a dot pattern, and by modulating which groups of VCSELs are active a density of the dot pattern may be adjusted. The VCSEL array may be part of a depth projector that projects the dot pattern into a local area. A projection assembly may replicate the dot pattern in multiple tiles.

In some implementations, an optical device (e.g., a monolithic master oscillator power amplifier (MOPA) diode) may include a first facet, one or more gratings, an amplifier structure terminated with a second facet, and an oscillator array that includes multiple singlemode oscillators coupled to the first facet and to the one or more gratings. In some implementations, the multiple singlemode oscillators may be configured to generate multiple seed beams and to transmit the multiple seed beams into the amplifier structure through the one or more gratings.

A multi-wavelength laser module including a base plate, a plurality of radiation sources mounted on the base plate, at least one telescope including a first lens and a second lens wherein the second lens is arranged at a distance from the first lens along a radiation beam path, thereby creating a telescopic effect. A beam angle correction plate is arranged between the first lens and the second lens in the radiation beam path, the beam angle correction plate being angled in relation to the radiation beam path so as to parallel shift the radiation beam inside the telescope and thereby adjust the pointing direction of the radiation beam after passage of the telescope. Further, a method for assembling a multi-wavelength laser system provided with telescopes with such beam angle correction plate.