An optical transmission device includes: a memory; and a processor coupled to the memory; the processor: generate a first symbol by mapping a transmission data series to a first signal point which belongs to a first group within a signal space defined with regard to characteristics of an optical carrier wave of the transmission data series; generate a second symbol by mapping the transmission data series to a second signal point belonging to a second group; calculate a perturbation quantity of a signal electric field for each of the first and second symbols based on signal electric field vector information of a symbol which is generated before the first symbol and the second symbol; and determine, as a transmission signal, a symbol having a smaller perturbation quantity between the first symbol and the second symbol.

A configuration for receiving transmission data at multiple rates where one rate is not necessarily a multiple of another is provided. A host board includes a receiving circuit, a cross point switch, and a switch control circuit. The receiving circuit includes a receiving unit configured to receive a first data signal transmitted at a first rate, and a second receiving unit configured to receive a second data signal transmitted at a second rate different from the first rate. The cross point switch includes input terminals and output terminals. The cross point switch is configured to define a path of signal between the input terminals and the output terminals to route an input data signal to at least one of the first receiving unit and the second receiving unit.

Disclosed is a method for optimizing optical fibre based transmission, in particular increasing span length and/or minimizing energy consumption and cost for an optical fibre based transmission link, and the so optimized fibre based transmission link. Further disclosed is a method for minimizing the energy consumption and/or the cost of an optical fibre based transmission link by doubling the number of fibre channels. Also disclosed is a method for minimizing the energy consumption and/or the cost of a repeaterless optical fibre based transmission link.

A configuration for receiving transmission data at multiple rates where one rate is not necessarily a multiple of another is provided. A host board includes a receiving circuit, a cross point switch, and a switch control circuit. The receiving circuit includes a receiving unit configured to receive a first data signal transmitted at a first rate, and a second receiving unit configured to receive a second data signal transmitted at a second rate different from the first rate. The cross point switch includes input terminals and output terminals. The cross point switch is configured to define a path of signal between the input terminals and the output terminals to route an input data signal to at least one of the first receiving unit and the second receiving unit.

Disclosed herein are methods, devices, and systems for providing timing and bandwidth management of ultra-wideband, wireless data channels (including radio frequency and wireless optical data channels). According to one embodiment, a hub adapter includes a first high-speed computer peripheral interface, first digital circuitry coupled with the high-speed computer peripheral interface; and a first free-space-optical (FSO) transmitter coupled with the digital circuitry, and a first FSO receiver coupled with the digital circuitry. The first FSO transmitter is configured to transmit a data channel and an out-of-band control signal comprising timing information and bandwidth management information to a computer peripheral adapter and the data channel is configured to operate at a bit rate greater than 1 gigabits per second (Gbps).

There is provided an optical transmission device including: a first coupler to which an optical signal including an amplified spontaneous emission is input; a first filter configured to transmit the optical signal having a first frequency band from the first coupler; a first optical detector configured to detect an optical intensity of the optical signal transmitted through the first filter; a first port coupled to the first coupler; a second port configured to be coupled to the first port; a second coupler coupled to the second port; a second filter configured to transmit the optical signal having a second frequency band matching the first frequency band from the second coupler; and a reflector configured to reflect the optical signal from the second filter.

Disclosed herein are methods, devices, and systems for providing timing and bandwidth management of ultra-wideband, wireless data channels (including radio frequency and wireless optical data channels). According to one embodiment, a hub adapter includes a first high-speed computer peripheral interface, first digital circuitry coupled with the high-speed computer peripheral interface; and a first free-space-optical (FSO) transmitter coupled with the digital circuitry, and a first FSO receiver coupled with the digital circuitry. The first FSO transmitter is configured to transmit a data channel and an out-of-band control signal comprising timing information and bandwidth management information to a computer peripheral adapter and the data channel is configured to operate at a bit rate greater than 1 gigabits per second (Gbps).

Embodiments of an optical amplification apparatus are disclosed which include a first optical amplifier, a second optical amplifier, and a mode exchanger. The first optical amplifier is connected to an input port of the mode exchanger, and the second optical amplifier is connected to an output port of the mode exchanger. The first optical amplifier is configured to amplify optical signals carried in a plurality of transmission modes of a few-mode fiber, the plurality of transmission modes of the few-mode fiber may be grouped into N groups, each group includes two transmission modes, and N is a positive integer greater than or equal to 1. The mode exchanger is configured to exchange the two transmission modes carrying optical signals in each group. The second optical amplifier is configured to amplify the optical signals that are carried in the two transmission modes in each group and whose modes are exchanged.

Methods, systems, and devices for wireless communications are described. Techniques described herein provide for a user equipment (UE) with a Modulated Retro Reflector (MRR) to support full duplex Optical Wireless Communications. To achieve full duplex communication, the UE and a network entity may use compatible modulation schemes for downlink communications and uplink communications. The UE and network entity may negotiate and agree upon compatible the uplink and downlink modulation schemes. The UE may receive a downlink OWC transmission using the downlink modulation scheme and transmit an uplink OWC transmission via modulating the downlink transmission in accordance with the uplink modulation scheme.