Provided is a multi-channel, bi-directional optical communication module. The multi-channel, bi-directional optical communication module includes a transmission unit transmitting an optical transmission signal for each of a plurality of channels, a multiplexer multiplexing the transmitted optical transmission signal for each of the plurality of channels to output a multi-channel optical transmission signal, a circulator passing the multi-channel optical transmission signal output from the multiplexer therethrough to transmit the multi-channel optical transmission signal to an optical fiber and reflecting a multi-channel optical reception signal received from the optical fiber, a demultiplexer demultiplexing the multi-channel optical reception signal reflected from the circulator to output an optical reception signal for each of the plurality of channels, a reception unit receiving the output optical reception signal for each of the plurality of channels and converting the received optical reception signal into an electrical signal for each of the plurality of channels, and a body unit in which the transmission unit, the multiplexer, the circulator, the demultiplexer, and the reception unit are disposed, in which a wavelength of the optical transmission signal for each of the plurality of channels is the same as a wavelength of the optical reception signal for each of the plurality of channels, and the circulator includes a first optical filter which passes a multi-channel optical transmission signal incident to a surface thereof therethrough and reflects a multi-channel optical reception signal incident to the other surface thereof, and a second optical filter which is disposed in parallel with the first optical filter and reflects the multi-channel optical reception signal reflected from the first optical filter to the demultiplexer.

Process margin relaxation is provided in relation to a compensated-for process via a first optical device, fabricated to satisfy an operational specification when a compensated-for process is within a first tolerance range; a second optical device, fabricated to satisfy the operational specification when the compensated-for process is within second tolerance range, different than the first tolerance range; a first optical switch connected to an input and configured to output an optical signal received from the input to one of the first optical device and the second optical device; and a second optical switch configured to combine outputs from the first optical device and the second optical device.

An input/output, a wavelength multiplexer/demultiplexer, and a spatial light modulator are provided. The input/output is configured by an optical waveguide into which multiplex light with multiple wavelengths enters. The wavelength multiplexer/demultiplexer performs demultiplexing for forming a plurality of signal lights by spatially demultiplexing the multiplex light emitted from the input/output, by one diffraction, into light of each wavelength, and multiplexing for multiplexing the spatially demultiplexed plurality of signal lights that are different in wavelength. The wavelength multiplexer/demultiplexer is configured by a metasurface. The spatial light modulator reflects each of the plurality of signal lights in a set direction.

A wavelength division multiplexing device includes a common port and a plurality of filters that define an optical path. The common port includes a collimator that transmits an optical beam including a plurality of optical signals. Each optical signal is associated with a different wavelength range, and each filter includes an interface having a radius of curvature. One filter is configured to receive the optical beam from the collimator, transmit an optical signal through its interface, and reflect the remaining portion of the optical beam toward another filter. The common collimator and filter are configured so that the reflected portion of the optical beam has a beam waist located in the optical path midway between the filters, and a wavefront radius of curvature at the other filter that matches the filter radius of curvature of that filter. A method of processing light in such a device is also disclosed.

An edge wavelength-switching system includes an optical switch and a wavelength selective switch. The optical switch includes a west hub-side port, an east hub-side port, a west local-side port, and an east local-side port. The wavelength selective switch includes (i) a multiplexed port optically coupled to the west local-side port and (ii) a bypass port optically coupled to the east local-side port, and (iii) a plurality of demultiplexed ports. An optical network includes a network hub including an M-by-N.sub.1 wavelength-selective switch, N.sub.1>M≥1, a first network node, and a second network node. Each of the first and second network nodes includes a respective edge wavelength-switching system. The network hub, the first network node, and the second network node are optically coupled.

Device and method for processing an optical signal. The device includes a photonic device arranged between a first input/output and second input/output and optically communicating with the inputs/outputs by a signal path for transmission of an optical signal in a first or second direction between the first input/output and second input/output. The device includes an optical gain element for amplifying the optical signal. The device includes a path switching circuit including a first signal amplification path connectable between the first input/output and the photonic device for optically coupling the signal path to and from the optical gain element, and a second signal amplification path connectable between the photonic device and the second input/output for optically coupling the signal path to and from the optical gain element. The path switching circuit selectively connects the first or second signal amplification path into the signal path.

An optical line terminal (OLT) includes: a first optical transceiver and a second optical transceiver each configured to transmit or receive at least one optical signal among an optical signal of a first standard and an optical signal of a second standard through an optical cable inserted thereinto, and convert between an optical signal and an electrical signal; a first connector configured to electrically connect an extended output terminal of an electrical signal input/output unit of the first transceiver and an extended output terminal of an electrical signal input/output unit of the second optical transceiver; and a second connector configured to selectively connect the extended output terminal and a default output terminal of the electrical signal input/output unit of the second optical transceiver.

An apparatus includes a reconfigurable optical add/drop multiplexer (ROADM) having an input port to receive a first optical signal from a second device. The ROADM also includes a first wavelength selective switch (WSS), in optical communication with the input port, to convert the first optical signal into a second optical signal, a loopback, in optical communication with the first WSS, to transmit the second optical signal, and a second WSS, in optical communication with the loopback, to convert the second optical signal to a third optical signal and direct the third optical signal back to the second device via the input port.

An input/output, a wavelength multiplexer/demultiplexer, and a spatial light modulator are provided. The input/output is configured by an optical waveguide into which multiplex light with multiple wavelengths enters. The wavelength multiplexer/demultiplexer performs demultiplexing for forming a plurality of signal lights by spatially demultiplexing the multiplex light emitted from the input/output, by one diffraction, into light of each wavelength, and multiplexing for multiplexing the spatially demultiplexed plurality of signal lights that are different in wavelength. The wavelength multiplexer/demultiplexer is configured by a metasurface. The spatial light modulator reflects each of the plurality of signal lights in a set direction.

Provided is a multi-channel, bi-directional optical communication module. The multi-channel, bi-directional optical communication module includes a transmission unit transmitting an optical transmission signal for each of a plurality of channels, a multiplexer multiplexing the transmitted optical transmission signal for each of the plurality of channels to output a multi-channel optical transmission signal, a circulator passing the multi-channel optical transmission signal output from the multiplexer therethrough to transmit the multi-channel optical transmission signal to an optical fiber and reflecting a multi-channel optical reception signal received from the optical fiber, a demultiplexer demultiplexing the multi-channel optical reception signal reflected from the circulator to output an optical reception signal for each of the plurality of channels, a reception unit receiving the output optical reception signal for each of the plurality of channels and converting the received optical reception signal into an electrical signal for each of the plurality of channels, and a body unit in which the transmission unit, the multiplexer, the circulator, the demultiplexer, and the reception unit are disposed, in which a wavelength of the optical transmission signal for each of the plurality of channels is the same as a wavelength of the optical reception signal for each of the plurality of channels, and the circulator includes a first optical filter which passes a multi-channel optical transmission signal incident to a surface thereof therethrough and reflects a multi-channel optical reception signal incident to the other surface thereof, and a second optical filter which is disposed in parallel with the first optical filter and reflects the multi-channel optical reception signal reflected from the first optical filter to the demultiplexer.