A tunable optical filter integrates the functions of wavelength tuning and power isolation of back reflection. The optical signal enters a Faraday rotator twice, and isolation is provided by two birefringent crystals, having their optical axes oriented at 45 degrees with respect to each other. The two birefringent crystals are on the same side of the Faraday rotator. The integration of an optical tunable filter and an isolator function into a single packaged component helps to reduce the size and complexity of optical amplifier systems, such as EDFAs and PDFAs, operating in the 1550 nm and 1310 nm transmission bands, respectively.

A digital-electrical to analog-optical converter for converting a N-bit digital data signal uses a non-linear optical element that is susceptible to the Kerr effect. N digitally modulated optical bit stream sources are co-polarized and modulated according to individual bit streams of the digital data. The co-polarized digitally modulated signals interact with a polarized probe signal in the optical element causing the polarization of the probe signal to be changed. Propagating the polarization-changed probe signal output from the optical element through a polarizer provides an amplitude modulated optical signal corresponding to the N-bit digital signal.

Medical imaging camera head devices and methods are provided using light captured by an endoscope system or other medical scope or borescope. Afocal light from the scope is manipulated and split by a beamsplitter. At least one polarizing optical element manipulates the polarization properties of one or both of the beams. The resulting first and second beams are passed through focusing optics to different image sensor areas to produce images with different intensity. The resulting images are combined with high dynamic range techniques.

In various embodiments, a beam-parameter adjustment system and focusing system alters a spatial power distribution of a radiation beam, via thermo-optic effects, before the beam is coupled into an optical fiber or delivered to a workpiece.

This application discloses an optical communications apparatus, which may be a reconfigurable optical add/drop multiplexer. An optical deflection component (211) may perform angle deflection on a plurality of first sub-wavelength light beams to obtain a plurality of second sub-wavelength light beams and a plurality of third sub-wavelength light beams, and propagate the plurality of second sub-wavelength light beams to a second optical switch array (205). A third wavelength dispersion component (206) combines the plurality of second sub-wavelength light beams into a second light beam. A first output component (207) outputs the second light beam from a dimension. A second wavelength dispersion component (208) combines the plurality of third sub-wavelength light beams into a third light beam, and makes the third light beam incident to a third optical switch array (209). A second output component (210) outputs the third light beam to drop a signal.

An illumination optical system includes: a beam splitter located near a conjugate position of a specimen and configured to split beams from a light source into a plurality of groups of beams having different splitting directions around an optical axis; a beam selector configured to select and transmit one group of beams from the plurality of groups of beams and that is rotatable with respect to the optical axis; and a ½ wavelength plate located near the beam selector and rotatable about the optical axis. The rotation angles of the ½ wavelength plate and of the beam selector about the optical axis are respectively set so that the polarization direction of the beam which has passed through the ½ wavelength plate is perpendicular to the splitting direction of the one group of beams that has been selected by the beam selector and split by the beam splitter.

A single-fiber bidirectional optical transceiver module of the same wavelength. A sub-wavelength grating and a Faraday rotator are used, and the same element is reused to implement a polarization multiplex/de-multiplex function, so as to implement transmission and receiving of an optical signal in a small space. The single-fiber bidirectional optical transceiver module has less optical elements, a compact structure, and low cost, meeting the needs on a miniaturized, integrated, and high speed optical transceiver module for a modern optical communication system.

There is provided a light-guide, compact collimating optical device, including a light-guide having a light-waves entrance surface, a light-waves exit surface and a plurality of external surfaces, a light-waves reflecting surface carried by the light-guide at one of the external surfaces, two retardation plates carried by light-guides on a portion of the external surfaces, a light-waves polarizing beamsplitter disposed at an angle to one of the light-waves entrance or exit surfaces, and a light-waves collimating component covering a portion of one of the retardation plates. A system including the optical device and a substrate, is also provided.

In various embodiments, a beam-parameter adjustment system and focusing system alters a spatial power distribution of a plurality of radiation beams before the beams are coupled into an optical fiber.

Advantageously, at least one embodiment of the present disclosure comprises a polarization maintaining PROFA (“PM-PROFA”) coupler in which the polarization axes of the individual vanishing core waveguides thereof are oriented or aligned without the need to adjust the orientation of each individual VC waveguide.