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.

Described herein is a wavelength selective switch (WSS) type optical switching device (1) configured for switching input optical beams from input optical fiber ports (3, 5 and 7) to an output optical fiber port (9). Device (1) includes a wavelength dispersive grism element (13) for spatially dispersing the individual wavelength channels from an input optical beam in the direction of a second axis (y-axis). The optical beams propagate from input ports (3, 5 and 7) in a forward direction and are reflected from a liquid crystal on silicon (LCOS) device (11) in a return direction to output port (9). The input optical beams are transmitted through a port selecting module (21), which provides polarization diversity to device (1) and provides capability to restrict optical beams returning from LCOS device (11) from being coupled back into input ports (3, 5 and 7).

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.

The present invention provides a wavelength division multiplexing/demultiplexing optical transceiving assembly based on a diffraction grating, which is an uplink optical emitting unit and a downlink optical receiving unit that comprise a laser chip array, a light receiving detector array, a first fast axis collimating lens, a second fast axis collimating lens, a first slow axis collimating lens, a diffraction grating, a slow axis focusing lens, a second slow axis collimating lens, an optical isolator, a coupling output lens, a coupling input lens, a coupling outputting optical fiber and a coupling inputting optical fiber. The wavelength division multiplexing/demultiplexing optical transceiving assembly solves the technical problem of sharing a diffraction grating to realize a wavelength division multiplexing/demultiplexing function, achieves the beneficial effects of better diffraction grating filtering property, smaller light path coupling loss and insertion loss correlative with wavelength, larger independent optical element sizes, and simpler assembly process, and is more suitable for manufacturing a multi-channel wavelength division multiplexing/demultiplexing optical transceiving assembly.

An integrated optical component includes at least one input waveguide, at least one output waveguide; a first slab waveguide having a first refractive index, n1. The first slab waveguide may be disposed between at least one of the input waveguides and at least one of the output waveguides. The integrated optical component may further include a second slab waveguide having a second refractive index, n2. The integrated optical component may also include a third cladding slab having a third refractive index, n3. The third cladding slab may be disposed between the first slab and the second slab. The thickness of the second slab waveguide and the thickness of the third slab waveguide are adjustable to reduce a birefringence of the integrated optical component.

A wavelength selective switch includes an attenuation liquid crystal cell array and a switching liquid crystal cell array, the attenuation liquid crystal cell array is configured to select a region where a light is incident on the switching liquid crystal cell array; the switching liquid crystal cell array includes a first ECB liquid crystal cell array, which is divided into a plurality of pixel units, a phase of each pixel unit is adjusted by setting different voltages so that a phase pattern formed by the pixel units exhibits a lens property, and the light passing through the switching liquid crystal cell array is deflected by changing a center of the lens formed by the phase pattern, so as to select an outgoing port.

A self-fit optical filter includes a dual fiber collimator, a diffraction grating for spatially dispersing the input light beam into a plurality of sub-beams, a cylindrical lens for focusing each of the sub-beams at a saturable absorber which becomes saturated dependent on intensity of light, and a reflector for reflecting the sub-beams back along their optical paths. A method of filtering includes: demultiplexing an input beam into a plurality of sub-beams having distinct center wavelengths, at least partially absorbing one or more of the sub-beams by using a saturable absorber while allowing other sub-beams to pass through, substantially unattenuated, and multiplexing the sub-beams into an output optical signal.

An optical communication system that includes a data transmitter which includes: at least one ultraviolet laser source configured to output ultraviolet light energy as an optical beam having an operating bandwidth with at least one communication band; a frequency presence modulation unit including at least one optical component having an ultraviolet coating, the frequency presence modulation unit being configured to: spectrally segregate the bandwidth of the at least one communication band into plural channels, and modulate the bandwidth to selectively produce an ultraviolet optical output signal with wavelengths that correspond to one or more of the channels, wherein a presence and absence of energy within channels of the communication band will constitute an information packet for data communication; and a controller for providing a control signal to the frequency presence modulation unit to spectrally segregate the bandwidth of the at least one communication band into the plural channels.

A quantum memory device and methods for storage and retrieval of a qubit from the quantum memory device are described. The quantum memory device includes a first optical component to convert an input qubit encoded in an arbitrary polarization state of a photon into a spatial qubit propagating in a pair of parallel optical rails, an atomic vapor memory to store the spatial qubit in an atomic vapor, and a second optical component to combine the spatial qubit, when retrieved from the atomic vapor memory, into an output qubit encoded in an arbitrary polarization state of a photon.

A wavelength selective switch (WSS) apparatus is disclosed, which includes: a liquid crystal on silicon (LCOS) phase array configured for selectively diverting a certain wavelength component of light beams to continue to propagate and keeping another wavelength component of the light beams from propagating by controlling a voltage applied thereto and/or a polarization of the light beams, the LCOS phase array being provided with a first liquid crystal (LC) domain, a second liquid crystal (LC) domain, and a reflection component, the reflection component being configured to reflect a light beam input through the first LC domain back to the first LC domain and reflect a light beam input through the second LC domain back to the second LC domain; and a reflective element that is arranged to reflect the light beams output from the LCOS phase array back to the LCOS phase array.