An optical modulator combines and inputs a signal light propagating through the optical network and a control light having information concerning the optical network to a nonlinear optical medium. The optical modulator modulates the signal light according to changes in intensity of the control light, in the nonlinear optical medium.

An optical modulator combines and inputs a signal light propagating through the optical network and a control light having information concerning the optical network to a nonlinear optical medium. The optical modulator modulates the signal light according to changes in intensity of the control light, in the nonlinear optical medium.

An optical relay device is provided which is capable of outputting control signal light without equipping a light source for the control signal light and capable of flexibly managing and changing a wavelength of the control signal light in accordance with a state of a network. The optical relay device includes an optical receiving unit that receives a wavelength multiplexed optical signal, a control unit that specifies a first wavelength and outputting notification information, and a processing unit that selects an optical signal having the first wavelength from the received wavelength multiplexed optical signal, applying intensity-modulation in accordance with the notification information to the selected optical signal, adding the intensity-modulated optical signal back to the wavelength multiplexed optical signal, and outputting the wavelength multiplexed optical signal.

An optical relay device is provided which is capable of outputting control signal light without equipping a light source for the control signal light and capable of flexibly managing and changing a wavelength of the control signal light in accordance with a state of a network. The optical relay device includes an optical receiving unit that receives a wavelength multiplexed optical signal, a control unit that specifies a first wavelength and outputting notification information, and a processing unit that selects an optical signal having the first wavelength from the received wavelength multiplexed optical signal, applying intensity-modulation in accordance with the notification information to the selected optical signal, adding the intensity-modulated optical signal back to the wavelength multiplexed optical signal, and outputting the wavelength multiplexed optical signal.

In a signal regeneration device in which recovery of a signal quality which has been degraded during transmission in optical communication and extension of a transmission distance are achieved, the most representative method of quantizing an optical phase is a phase sensitive amplifier (PSA) and a technique that utilizes an optical parametric process through use of a highly nonlinear optical medium, but there is a demand for a technique of quantizing an optical phase which is not accompanied with an optical parametric gain, has small-sized elements, is easily integrated, and does not require high power pump light. By a technique of a hybrid optical phase squeezer (HOPS), when a phase of input light is quantized to M levels (M>2), phase conjugate light of the input light and (M1)th phase harmonic light of the input light are subjected to power modulation to be coherently added, so that quantization of the optical phase is performed through use of a simple four-wave mixing (FWM) that is not accompanied with the optical parametric gain and a general optical amplifier by using a general nonlinear optical medium such as silicon, and accordingly, a GER of equal to or higher than 30 dB can be obtained, even if a nonlinear optical element having a low nonlinearity is used.

In a signal regeneration device in which recovery of a signal quality which has been degraded during transmission in optical communication and extension of a transmission distance are achieved, the most representative method of quantizing an optical phase is a phase sensitive amplifier (PSA) and a technique that utilizes an optical parametric process through use of a highly nonlinear optical medium, but there is a demand for a technique of quantizing an optical phase which is not accompanied with an optical parametric gain, has small-sized elements, is easily integrated, and does not require high power pump light. By a technique of a hybrid optical phase squeezer (HOPS), when a phase of input light is quantized to M levels (M>2), phase conjugate light of the input light and (M1)th phase harmonic light of the input light are subjected to power modulation to be coherently added, so that quantization of the optical phase is performed through use of a simple four-wave mixing (FWM) that is not accompanied with the optical parametric gain and a general optical amplifier by using a general nonlinear optical medium such as silicon, and accordingly, a GER of equal to or higher than 30 dB can be obtained, even if a nonlinear optical element having a low nonlinearity is used.

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).

An all-optical signal regeneration technique in which a modulation alphabet is mapped on to a set of optimised points of a regenerative transfer function. The optimised points correspond to attraction regions in the regenerative transfer function and are preferably stable. The regenerative transfer function can be selected to be the Fourier transform of an ideal regenerator, which is represented by a step-wise transfer function. Use of the Fourier transform can enable efficient regeneration of multilevel multidimensional signals. The regenerative Shannon limitthe upper bound of regeneration efficiency can also be derived.

An all-optical signal regeneration technique in which a modulation alphabet is mapped on to a set of optimised points of a regenerative transfer function. The optimised points correspond to attraction regions in the regenerative transfer function and are preferably stable. The regenerative transfer function can be selected to be the Fourier transform of an ideal regenerator, which is represented by a step-wise transfer function. Use of the Fourier transform can enable efficient regeneration of multilevel multidimensional signals. The regenerative Shannon limitthe upper bound of regeneration efficiency can also be derived.

An optical device equips a piece of communication equipment of an optical wireless communication network, and includes a monolithic optical element including at least one ruled optical surface having a curved generatrix selected to present an orientation that varies harmonically as a function of angular position, so as to spatially orient a radiation pattern for transmission and/or a radiation pattern for reception of light waves.