Embodiments of the present invention provide a liquid crystal grating-based optical switching apparatus, including an input collimator, an input polarization beam splitter, an input quarter-wave plate, a liquid crystal grating, an output quarter-wave plate, an output polarization beam splitter, and an output collimator. A transmission path is selected for an optical signal by changing a voltage of a liquid crystal grating so that the optical signal is output to a selected output.

Embodiments of the present invention provide a liquid crystal grating-based optical switching apparatus, including an input collimator, an input polarization beam splitter, an input quarter-wave plate, a liquid crystal grating, an output quarter-wave plate, an output polarization beam splitter, and an output collimator. A transmission path is selected for an optical signal by changing a voltage of a liquid crystal grating so that the optical signal is output to a selected output.

Embodiments of the present invention provide an optical communications apparatus, where the apparatus includes: an input system, a first optical switch array, and an output system, where the input system includes N input ports that are one-dimensionally arranged on a first plane, a first beam expander, a demultiplexer, and a first optical path changer; the first optical switch array includes NK first optical switch units that are two-dimensionally arranged on a second plane, and the first optical switch units can rotate in a first axial line direction and a second axial line direction; and the output system includes a second optical path changer, a second beam expander, a second optical switch array, and M output ports that are two-dimensionally arranged.

An optical module that implements an MMI device including an optical hybrid primarily made of semiconductor material is disclosed. The MMI device, which has a rectangular plane shape and includes multi-mode couplers, is mounted on a carrier. The carrier provides a step extending in a whole lateral width of a top surface thereof, where the step makes a gap against the MMI device in an area where the MMI couplers are formed.

A device for coupling a laser beam into a multi-clad fiber includes a beam switch for dividing the laser beam into a plurality of sub-laser-beams. The beam switch includes at least two birefringent optical wedges, and at least one polarization-influencing device having an adjustable polarization-influencing effect and being arranged between the at least two birefringent optical wedges. The device further includes an in-coupling optical unit for coupling the plurality of sub-laser-beams exiting the beam switch into the multi-clad fiber. The in-coupling optical unit is configured to couple at least two of the plurality of sub-laser-beams exiting the beam switch into at least two different light-conducting cores of the multi-clad fiber.

A curved reflective polarizer includes a plurality of polymeric layers stretched and shaped along at least orthogonal first and second directions so that at least one location on the curved reflective polarizer has a radius of curvature in a range from about 6 mm to about 1000 mm along each of the first and second directions. For light having a predetermined wavelength and incident on the reflective polarizer along a direction parallel to an optical axis normal to and passing through the reflective polarizer at a center of the reflective polarizer, each location on the reflective polarizer has a maximum reflectance 10 greater than about 70% and a corresponding minimum transmittance less than about 5% for a block polarization state.