The disclosure provides an optical transmission system and an optical matrix. The optical transmission system includes a first optical transmitter, an optical matrix, and a first optical receiver. The first optical transmitter receives a first video electrical signal corresponding to a first video standard, and converts the first video electrical signal into a first optical signal at a specified transmission rate. The optical matrix is used to receive and forward the first optical signal. The first optical receiver receives the first optical signal at the specified transmission rate forwarded by the optical matrix, and converts the first optical signal into a second video electrical signal corresponding to a second video standard.

A combinatorial optimization problem processing device is for associating a combinatorial optimization problem having N elements with an Ising model to process the combinatorial optimization problem. The combinatorial optimization problem processing device includes: a 1×2 Mach-Zehnder optical modulator that receives a polarized clock pulse train; an optical interference circuit that receives polarized clock pulse trains that were modulated by the Mach-Zehnder optical modulator; an optical coupler that couples output of the optical interference circuit with an initialization optical pulse train that creates a neutral state with respect to interactions between the elements; and a modulation signal generator that performs waveform shaping on an electrical signal obtained by photoelectrically converting an output signal of the optical coupler, generates a modulation signal for the Mach-Zehnder optical modulator, and externally outputs a monitor signal that represents a solution to the optimization problem. The optical interference circuit repeatedly allows a predetermined interaction in the Ising model to occur from the neutral state at a period corresponding to the N pulses of the polarized clock pulse train.

A communication module includes a laser driving unit (LDU) and one or more multifunction illumination units. The one or more multifunction illumination units are be coupled to the LDU with an electrical connection and configured to transmit both electrical power and data.

Methods, systems, and devices for quantum key distribution (QKD) in passive optical networks (PONs) are described. A PON may be a point-to-multipoint system and may include a central node in communication with multiple remote nodes. In some cases, each remote node may include a QKD transmitter configured to generate a quantum pulse indicating a quantum key, a synchronization pulse generator configured to generate a timing indication of the quantum pulse, and filter configured to output the quantum pulse and the timing indication to the central node via an optical component (e.g., an optical splitter, a cyclic arrayed waveguide grating (AWG) router). The central node may receive the timing indications and quantum pulses from multiple remote nodes. Thus, the central node and remote nodes may be configured to communicate data encrypted using quantum keys.

Methods, systems, and devices for quantum key distribution (QKD) in passive optical networks (PONs) are described. A PON may be a point-to-multipoint system and may include a central node in communication with multiple remote nodes. In some cases, each remote node may include a QKD transmitter configured to generate a quantum pulse indicating a quantum key, a synchronization pulse generator configured to generate a timing indication of the quantum pulse, and filter configured to output the quantum pulse and the timing indication to the central node via an optical component (e.g., an optical splitter, a cyclic arrayed waveguide grating (AWG) router). The central node may receive the timing indications and quantum pulses from multiple remote nodes. Thus, the central node and remote nodes may be configured to communicate data encrypted using quantum keys.

Provided is an optical transceiver including: a controller configured to output firmware update data for updating firmware of another optical transceiver connected to the optical transceiver through an optical cable; and a transmitter configured to generate an optical signal by superposing input payload data and the firmware update data, and to transmit the optical signal to the other optical transceiver. According to embodiments, the firmware of a remote optical transceiver at a remote location is automatically updated without affecting payload data, which is information to be transmitted.

Provided is an optical transceiver including: a controller configured to output firmware update data for updating firmware of another optical transceiver connected to the optical transceiver through an optical cable; and a transmitter configured to generate an optical signal by superposing input payload data and the firmware update data, and to transmit the optical signal to the other optical transceiver. According to embodiments, the firmware of a remote optical transceiver at a remote location is automatically updated without affecting payload data, which is information to be transmitted.

Control instructions are transmitted to receivers by modulating light sources to generate light beams that are modulated with digital data streams for inducing control instructions in the light beams. Each light beam is applied to a pixel shaper element of a pixel shaper assembly to produce a light pixel, each light pixel carrying the control instructions of the light beam, each light pixel having a perimeter defined by the pixel shaper element. The pixel shaper assembly combines the light pixels into an image without significant overlap or voids between the light pixels. The light pixels are directed toward a projector lens for transmission toward the receivers. In a receiver, an optical receiver detects a light pixel. A controller decodes the control instructions received in the detected light pixel and uses the control instructions to control a function of the receiver.

Control instructions are transmitted to receivers by modulating light sources to generate light beams that are modulated with digital data streams for inducing control instructions in the light beams. Each light beam is applied to a pixel shaper element of a pixel shaper assembly to produce a light pixel, each light pixel carrying the control instructions of the light beam, each light pixel having a perimeter defined by the pixel shaper element. The pixel shaper assembly combines the light pixels into an image without significant overlap or voids between the light pixels. The light pixels are directed toward a projector lens for transmission toward the receivers. In a receiver, an optical receiver detects a light pixel. A controller decodes the control instructions received in the detected light pixel and uses the control instructions to control a function of the receiver.

Techniques are described for implementing an out-of-band communication channel used to exchange control channel information in sub-carrier-based optical communication systems. In an example implementation, an optical communication system includes a primary transceiver, a component, and secondary transceivers. The primary transceiver is operable to supply first optical subcarriers to an optical communication path, the first optical subcarriers being amplitude modulated at a first frequency to carry first control information and amplitude modulated at a second frequency to carry second control information. The component is operable to be coupled to the optical communication path and includes circuitry operable to detect the first control information. The secondary transceivers are coupled to a terminal end of the optical communication path. At least one of the secondary transceivers is operable to detect the second control information and block the first control information.