An optical amplification apparatus includes a plurality of input ends configured to receive a plurality of first optical signals with different wavelengths, a plurality of output ends configured to output a plurality of second optical signals obtained by amplifying the first optical signals, and a first pump source configured to provide a first pump light for amplifying the first optical signals. The apparatus also includes a first multi-port wavelength division multiplexing coupler having a plurality of first connection ports connected to the input ends. The apparatus further includes a first optical fiber connection cable connecting the first pump source with the first multi-port wavelength division multiplexing coupler. The first optical fiber connection cable is configured to transmit the first pump light. The apparatus additionally includes an active optical fiber connection cable having an active doped fiber for transmitting and amplifying a plurality of third optical signals.

A multi-core optical amplifying fiber includes: core portions doped with a rare-earth element; an inner cladding portion; and an outer cladding portion. A mode field diameter of each core portion at a wavelength at which the rare-earth element performs optical amplification is 5 μm to 11 μm, a relative refractive-index difference of the maximum refractive index of each core portion with respect to the inner cladding portion is 0.35% to 2%, a core-to-core distance is set such that total inter-core crosstalk is −40 dB/100 m or lower in an optical amplification wavelength band subjected to the optical amplification, a cladding thickness is smaller than a value obtained by adding the mode field diameter to a minimum value of the core-to-core distance, and a ratio of a total sectional area of the core portions to a sectional area of the inner cladding portion is 1.9% or more.

Optical transmission equipment includes an optical transceiver circuit that transmits and receives signal light and supervisory light, a forward Raman amplifier provided at a transmitter end of the optical transceiver circuit, a backward Raman amplifier provided at a receiver end of the optical transceiver circuit, and a processor that controls the forward Raman amplifier and the backward Raman amplifier. When a counterpart backward Raman amplifier or a counterpart forward Raman amplifier provided at an opposite side through a fiber-optic transmission line is started up, the processor turns off a power of the forward Raman amplifier or the backward Raman amplifier according to a supervisory signal received from the fiber-optic transmission line, and releases an off state of the forward Raman amplifier or the backward Raman amplifier after a predetermined period of time.

A light source includes: a seed light source configured to output incoherent seed light with a predetermined bandwidth; and a booster amplifier that is a semiconductor optical amplifier configured to optically amplify the seed light input from a first facet, and output the amplified seed light as amplified light from a second facet, wherein the first facet and the second facet of the booster amplifier are subjected to a reflection reduction treatment, the booster amplifier is configured to operate in a gain saturated state, and relative intensity noise (RIN) and ripple are simultaneously suppressed in the amplified light.

A modulation scheme conversion device includes: a backscattering tag to which a tag signal is provided; and a tag signal forming unit for forming a tag signal. The modulation scheme conversion device multiplies a radio signal, which has been modulated in a first modulation scheme, and a tag signal, and reconfigures the multiplied signal by using a second modulation scheme, so as to backscatter the reconfigured signal, wherein the reconfiguration is performed in a physical (PHY) layer.

Coherent optical multiplexing 1+1 protection disclosed herein uses multiplexers, each having multiplexing and demultiplexing sub-units. Relay ports of a node are connected with the multiplexers, and each relay port is configured to input and output optical signals with the corresponding multiplexer. Two transmission ports of the node are connected with disjoint paths and are configured to input and output optical signals therewith. The node includes: a first optical splitter having input ports connected with the relay ports and two output ports connected with the two transmission ports; an optical switch connected with the transmission ports respectively via two input interfaces; a second optical splitter, which is a 1×N optical splitter, having one input port connected with an output interface of the optical switch and having output ports connected with the relay ports. The solution is reliable in implementation, has low insertion loss, and has good transmission performance.

Coherent optical multiplexing 1+1 protection disclosed herein uses multiplexers, each having multiplexing and demultiplexing sub-units. Relay ports of a node are connected with the multiplexers, and each relay port is configured to input and output optical signals with the corresponding multiplexer. Two transmission ports of the node are connected with disjoint paths and are configured to input and output optical signals therewith. The node includes: a first optical splitter having input ports connected with the relay ports and two output ports connected with the two transmission ports; an optical switch connected with the transmission ports respectively via two input interfaces; a second optical splitter, which is a 1×N optical splitter, having one input port connected with an output interface of the optical switch and having output ports connected with the relay ports. The solution is reliable in implementation, has low insertion loss, and has good transmission performance.

Described herein are photonic integrated circuits (PICs) comprising a semiconductor optical amplifier (SOA) to output a signal comprising a plurality of wavelengths, a sensor to detect data associated with a power value of each wavelength of the output signal of the SOA, a filter to filter power values of one or more of the wavelengths of the output signal of the SOA, and control circuitry to control the filter to reduce a difference between a pre-determined power value of each filtered wavelength of the output signal of the SOA and the detected power value of each filtered wavelength of the output signal of the SOA.

An apparatus embodiment includes a remote control interface unit configured to accept an appliance control code carried in a radio frequency signal transmitted from a smart phone, extract the appliance control code from the radio frequency signal, send the extracted appliance control code to an optical frequency interface, and initiate transmission of an optical frequency signal including the appliance control code to an appliance configured to receive signals from an optical remote control.

An apparatus embodiment includes a remote control interface unit configured to accept an appliance control code carried in a radio frequency signal transmitted from a smart phone, extract the appliance control code from the radio frequency signal, send the extracted appliance control code to an optical frequency interface, and initiate transmission of an optical frequency signal including the appliance control code to an appliance configured to receive signals from an optical remote control.