A system for transmission of optical data signals has first optical processing circuitry for receiving a plurality of digital signals and applying at least one of a Hermite-Gaussian function, a Laguerre-Gaussian function or an Ince-Gaussian function to each of the received plurality of digital signals. The first optical processing circuitry also combines each of the at least one of the Hermite-Gaussian function, the Laguerre-Gaussian function or the Ince-Gaussian function applied plurality of digital signals into a single carrier signal. An optical transmitter transmits the single carrier signal. An optical receiver receives the transmitted single carrier signal. Second optical processing circuitry separates the at least one of the Hermite-Gaussian function, the Laguerre-Gaussian function or the Ince-Gaussian function applied digital signals of the single carries signal into separate signals and removes the at least one of the Hermite-Gaussian function, the Laguerre-Gaussian function or the Ince-Gaussian function applied to each of the plurality of digital signals. An elliptical core fiber transmits the single carrier signal from the optical transmitter to the optical receiver. The elliptical core fiber includes an elliptical core have a major axis and a minor axis.

A system for transmission of optical data signals has first optical processing circuitry for receiving a plurality of digital signals and applying at least one of a Hermite-Gaussian function, a Laguerre-Gaussian function or an Ince-Gaussian function to each of the received plurality of digital signals. The first optical processing circuitry also combines each of the at least one of the Hermite-Gaussian function, the Laguerre-Gaussian function or the Ince-Gaussian function applied plurality of digital signals into a single carrier signal. An optical transmitter transmits the single carrier signal. An optical receiver receives the transmitted single carrier signal. Second optical processing circuitry separates the at least one of the Hermite-Gaussian function, the Laguerre-Gaussian function or the Ince-Gaussian function applied digital signals of the single carries signal into separate signals and removes the at least one of the Hermite-Gaussian function, the Laguerre-Gaussian function or the Ince-Gaussian function applied to each of the plurality of digital signals. An elliptical core fiber transmits the single carrier signal from the optical transmitter to the optical receiver. The elliptical core fiber includes an elliptical core have a major axis and a minor axis.

A single-fiber bidirectional optical ring system includes: a central station; slave stations; and a network which connects the central station and the slave stations in a ring shape by optical fibers. The central station includes: a first single-fiber bidirectional optical transceiver connected in a clockwise direction of the network, which outputs a downstream optical signal of a second wavelength and receives an upstream optical signal of a first wavelength; a second single-fiber bidirectional optical transceiver connected in a counterclockwise direction of the network, which outputs a downstream optical signal of the second wavelength and receives an upstream optical signal of the first wavelength; and a first time synchronization control circuit that adjusts timings at which the downstream optical signals of the second wavelength are outputted, and causes the first and second single-fiber bidirectional optical transceivers to output the downstream optical signals of the second wavelength in different time slots.

A single-fiber bidirectional optical ring system includes: a central station; slave stations; and a network which connects the central station and the slave stations in a ring shape by optical fibers. The central station includes: a first single-fiber bidirectional optical transceiver connected in a clockwise direction of the network, which outputs a downstream optical signal of a second wavelength and receives an upstream optical signal of a first wavelength; a second single-fiber bidirectional optical transceiver connected in a counterclockwise direction of the network, which outputs a downstream optical signal of the second wavelength and receives an upstream optical signal of the first wavelength; and a first time synchronization control circuit that adjusts timings at which the downstream optical signals of the second wavelength are outputted, and causes the first and second single-fiber bidirectional optical transceivers to output the downstream optical signals of the second wavelength in different time slots.

In order to solve the problem that the power consumption of optical amplifiers is not optimized over the life time of a network whose capacity in use varies, an optical amplifier according to an exemplary aspect of the invention includes a gain medium for amplifying a plurality of optical channels, the gain medium including a plurality of cores through which the plurality of optical channels to propagate respectively and a cladding area surrounding the plurality of cores; monitoring means for monitoring the plurality of optical channels inputted into the gain medium and producing a monitoring result; a first light source configured to emit a first light beam to excite the cladding area; a second light source configured to emit a plurality of second light beams to excite each of the plurality of cores individually; and controlling means for making a decision as to whether each of the plurality of cores to transmit one of the plurality of optical channels based on the monitoring result, and controlling the first light source and the second light source based on the decision.

In order to solve the problem that the power consumption of optical amplifiers is not optimized over the life time of a network whose capacity in use varies, an optical amplifier according to an exemplary aspect of the invention includes a gain medium for amplifying a plurality of optical channels, the gain medium including a plurality of cores through which the plurality of optical channels to propagate respectively and a cladding area surrounding the plurality of cores; monitoring means for monitoring the plurality of optical channels inputted into the gain medium and producing a monitoring result; a first light source configured to emit a first light beam to excite the cladding area; a second light source configured to emit a plurality of second light beams to excite each of the plurality of cores individually; and controlling means for making a decision as to whether each of the plurality of cores to transmit one of the plurality of optical channels based on the monitoring result, and controlling the first light source and the second light source based on the decision.

A system for the Raman amplification of mode-division multiplexed optical signals at the telecom wavelengths in multimode optical fibers, and a method. A mode-division multiplexer (105) is used at the input of a multimode fiber (107) to inject signals (101), and continuous-wave pump waves at lower wavelength (102), on the different transverse modes of the fiber. A second mode-division multiplexer (106) is used at the output of the fiber to extract the amplified signals (103). The amplification of one or more signals is accomplished by inter-modal and intra-modal stimulated Raman scattering occurring between the fiber transverse modes carrying the signals and those carrying the pumps.

A system for the Raman amplification of mode-division multiplexed optical signals at the telecom wavelengths in multimode optical fibers, and a method. A mode-division multiplexer (105) is used at the input of a multimode fiber (107) to inject signals (101), and continuous-wave pump waves at lower wavelength (102), on the different transverse modes of the fiber. A second mode-division multiplexer (106) is used at the output of the fiber to extract the amplified signals (103). The amplification of one or more signals is accomplished by inter-modal and intra-modal stimulated Raman scattering occurring between the fiber transverse modes carrying the signals and those carrying the pumps.

A receiving apparatus and method for determining transmission characteristics of an optical waveguide in which the receiving apparatus includes a waveguide interface for receiving a mixed light beam having a plurality of modes from a multi-mode optical waveguide and for receiving a blended shifted light beam from the multimode optical waveguide, wherein the mixed light beam has an associated phase for each mode of the plurality of modes, and wherein the mixed shifted light beam has an associated shifted phase for each mode of the plurality of modes; and one or more processors for determining mode information for the intermixed light beam and shifted mode information for the intermixed shifted light beam using a trained neural network and for determining, for each mode of the plurality of modes, the respective associated phase using the intermixed shifted light beam.

A receiving apparatus and method for determining transmission characteristics of an optical waveguide in which the receiving apparatus includes a waveguide interface for receiving a mixed light beam having a plurality of modes from a multi-mode optical waveguide and for receiving a blended shifted light beam from the multimode optical waveguide, wherein the mixed light beam has an associated phase for each mode of the plurality of modes, and wherein the mixed shifted light beam has an associated shifted phase for each mode of the plurality of modes; and one or more processors for determining mode information for the intermixed light beam and shifted mode information for the intermixed shifted light beam using a trained neural network and for determining, for each mode of the plurality of modes, the respective associated phase using the intermixed shifted light beam.