A beam steering method and device are provided. The beam steering method includes outputting, from a hologram recording medium on which a plurality of signal light beams having different steering information are recorded, signal light beam having specific steering information, by making reference light having a specific characteristic incident on the hologram recording medium. The method further includes o obtaining information about an object existing in the external environment based on the output signal light.

Wavelength division multiplexing (WDM) has enabled telecommunication service providers to fully exploit the transmission capacity of optical fibers. State of the art systems in long-haul networks now have aggregated capacities of terabits per second. Moreover, by providing multiple independent multi-gigabit channels, WDM technologies offer service providers with a straight forward way to build networks and expand networks to support multiple clients with different requirements. In order to reduce costs, enhance network flexibility, reduce spares, and provide re-configurability many service providers have migrated away from fixed wavelength transmitters, receivers, and transceivers, to wavelength tunable transmitters, receivers, and transceivers as well as wavelength dependent add-drop multiplexer, space switches etc. However, to meet the competing demands for improved performance, increased integration, reduced footprint, reduced power consumption, increased flexibility, re-configurability, and lower cost it is desirable to exploit/adopt monolithic optical circuit technologies, hybrid optoelectronic integration, and microelectromechanical systems (MEMS).

A variable wavelength filter includes: an input optical fiber; a diffraction grating that disperses input light from the input optical fiber; a variable mirror that has a reflective surface, wherein an angle of the reflective surface is adjustable, the variable mirror reflects the input light dispersed by the diffraction grating, the input light reflected by the variable mirror passes through a normal optical path, the input light that passes through the normal optical path has a wavelength band defined based on the angle of the reflective surface, and the defined wavelength band has a center wavelength corresponding to the angle of the reflective surface; an output optical fiber that outputs a portion of the input light that has passed through the normal optical path; and an optical detector disposed on a propagation path of the input light from the input optical fiber to the output optical fiber.

A liquid crystal on silicon, a wavelength selective switch, an alignment direction obtaining method, and a method for manufacturing a liquid crystal on silicon. The liquid crystal on silicon has a first pixel area, and a first liquid crystal located in the first pixel area. The first liquid crystal is deflected in a plane perpendicular to a first panel, and is deflected towards a first direction in a plane parallel to the first panel. An alignment direction of the first partial alignment film located in the first pixel area is deflected towards a second direction relative to a polarization direction of an incident beam, and the second direction is opposite to the first direction to reduce a loss of a deflected beam.

A beam steering method and device are provided. The beam steering method includes outputting, from a hologram recording medium on which a plurality of signal light beams having different steering information are recorded, signal light beam having specific steering information, by making reference light having a specific characteristic incident on the hologram recording medium. The method further includes o obtaining information about an object existing in the external environment based on the output signal light.

A wavelength selective switching device comprises a plurality of input paths for receiving optical signals, a plurality of output paths for emitting the optical signals, and a switching unit for selectively directing the optical signals from the input paths to the output paths. The switching unit comprises a reflective area adapted to be concurrently illuminated by a first optical signal from a first input path among the plurality of input paths, and by a second optical signal from a second input path among the plurality of input paths, the second input path being different from the first input path, and to concurrently direct the first optical signal to a first output path among the plurality of output paths and the second optical signal to a second output path among the plurality of output paths, the second output path being different from the first output path. Said first output path and said second output path are spatially separated by said first input path and said second input path, or vice-versa.

Wavelength division multiplexing devices, and methods of forming the same, include a coupling lens and a waveguide, the lens being positioned over a mirror formed in a transmission path of the waveguide. The mirror reflects incoming light signals out of the transmission path through the lens and further reflects light signals coming from the lens and into the transmission path. An optical chip is positioned near a focal length of the lens. The optical chip has an optical filter configured to transmit a light signal at a first wavelength and to reflect received light signals at wavelengths other than the first wavelength.

An optical receiver, used in wavelength-division multiplexing, has multiple photodetectors per channel. The optical receiver comprises a demultiplexer to separate incoming light into different output waveguides, one output waveguide for each channel. A splitter is used in each output waveguide to split each output waveguide into two or more branches. A separate photodetector is coupled with each branch so that two or more photodetectors are used to measure each channel.

A variable wavelength filter includes: an input optical fiber; a diffraction grating that disperses input light from the input optical fiber; a variable mirror that has a reflective surface, wherein an angle of the reflective surface is adjustable, the variable mirror reflects the input light dispersed by the diffraction grating, the input light reflected by the variable mirror passes through a normal optical path, the input light that passes through the normal optical path has a wavelength band defined based on the angle of the reflective surface, and the defined wavelength band has a center wavelength corresponding to the angle of the reflective surface; an output optical fiber that outputs a portion of the input light that has passed through the normal optical path; and an optical detector disposed on a propagation path of the input light from the input optical fiber to the output optical fiber.

A liquid crystal on silicon, a wavelength selective switch, an alignment direction obtaining method, and a method for manufacturing a liquid crystal on silicon. The liquid crystal on silicon has a first pixel area, and a first liquid crystal located in the first pixel area. The first liquid crystal is deflected in a plane perpendicular to a first panel, and is deflected towards a first direction in a plane parallel to the first panel. An alignment direction of the first partial alignment film located in the first pixel area is deflected towards a second direction relative to a polarization direction of an incident beam, and the second direction is opposite to the first direction to reduce a loss of a deflected beam.