There is provided an optical signal processing device capable of RC in a complex space using optical intensity and phase information. An optical modulator controlled by an electric signal processing circuit modulates laser light, which is emitted from a laser light source, at a modulation period either or both of the intensity and phase values of the optical electric field. On the other hand, an input signal is also modulated by the optical modulator at a modulation period in the time domain so as to be an input signal. The converted input signal passes through an optical transmission path and enters an optical circulation circuit via an optical coupler. Part of the circulating light is branched into two by an optical coupler, and the branched light is converted into a complex intermediate signal at a coherent optical receiver. This complex intermediate signal demodulated at the coherent optical receiver is computed at an electric signal processing circuit, and thereby the operation as RC can be performed.

A resonant-structured optical transistor includes a nonlinear medium which generates a second harmonic wave through second-order nonlinear interaction with an incident pump wave, and generates an amplified signal wave and a converted wave having a difference frequency through second-order nonlinear interaction between the incident signal wave and the second harmonic wave, a first mirror which transmits, to the nonlinear medium, the pump wave or the signal wave, and reflects the second harmonic wave on one surface of the nonlinear medium, and a second mirror which transmits the pump wave, the signal wave, or the converted wave, and reflects the second harmonic wave on another surface of the nonlinear medium. The pump wave is incident to the nonlinear medium through the first mirror in a first operation mode, and the pump wave and the signal wave are incident to the nonlinear medium through the first mirror in a second operation mode.

A demodulator can include an optical resonator. The optical resonator can include a resonant cavity that extends between a first surface that is partially reflective and a second surface that is at least partially reflective. The first surface can receive a phase-modulated optical signal that has a time-varying phase. The resonant cavity can accumulate resonant optical signal energy based at least in part on the phase-modulated optical signal. The first surface can direct a fraction of the resonant optical signal energy out of the optical resonator to form an intensity-modulated optical signal that has a time-varying intensity. A data detector can receive at least a portion of the intensity-modulated optical signal and, in response, generate an intensity-modulated electrical signal that has a time-varying intensity that corresponds to the time-varying phase of the phase-modulated optical signal.

A demodulator can include an optical resonator. The optical resonator can include a resonant cavity that extends between a first surface that is partially reflective and a second surface that is at least partially reflective. The first surface can receive a phase-modulated optical signal that has a time-varying phase. The resonant cavity can accumulate resonant optical signal energy based at least in part on the phase-modulated optical signal. The first surface can direct a fraction of the resonant optical signal energy out of the optical resonator to form an intensity-modulated optical signal that has a time-varying intensity. A data detector can receive at least a portion of the intensity-modulated optical signal and, in response, generate an intensity-modulated electrical signal that has a time-varying intensity that corresponds to the time-varying phase of the phase-modulated optical signal.

Disclosed are optical communications systems and optical receivers including one or more optical cavity resonators. In particular, disclosed are methods and apparatus that allow for beam pointing to be maintained while permitting the receiver to tune the optical resonator to suit the wavelength, data rate and modulation format of the incoming optical signal, without requiring a coherent receiver or adaptive optics in addition to optical resonators.

A pluggable optical connector is configured to be insertable into and removable from an optical communication apparatus, and to be capable of communicating a modulation signal and a data signal with the optical communication apparatus. A wavelength-tunable light source is configured to output an output light and a local oscillation light. An optical transmission unit is configured to output an optical signal generated by modulating the output light in response to the modulation signal. An optical reception unit is configured to demodulate an optical signal received by using the local oscillation light to the data signal. Pluggable optical receptors are configured in such a manner that an optical fiber is insertable into and removable from the pluggable optical receptors, and configured to be capable of outputting the optical signal to the optical fiber and transferring the optical signal received thorough the optical fiber to the optical reception unit.

A pluggable optical connector is configured to be insertable into and removable from an optical communication apparatus, and to be capable of communicating a modulation signal and a data signal with the optical communication apparatus. A wavelength-tunable light source is configured to output an output light and a local oscillation light. An optical transmission unit is configured to output an optical signal generated by modulating the output light in response to the modulation signal. An optical reception unit is configured to demodulate an optical signal received by using the local oscillation light to the data signal. Pluggable optical receptors are configured in such a manner that an optical fiber is insertable into and removable from the pluggable optical receptors, and configured to be capable of outputting the optical signal to the optical fiber and transferring the optical signal received thorough the optical fiber to the optical reception unit.

The present invention relates to an imaging system, including: a coherent light source delivering an object beam and a reference beam; a device of modulation of the object beam with a modulation signal; an image sensor arranged to receive an interference pattern resulting from a combination of the object beam and of the reference beam; and a demodulation device, the system being configured to, during a measurement phase: apply to the modulation signal a first pseudo-random sequence of jumps of a parameter selected among the phase, the frequency, and the amplitude; and simultaneously apply to the modulated portion of the object beam a second pseudo-random sequence of jumps of said parameter, wherein the first and second sequences of jumps of said parameter are non-correlated.

The present invention relates to an imaging system, including: a coherent light source delivering an object beam and a reference beam; a device of modulation of the object beam with a modulation signal; an image sensor arranged to receive an interference pattern resulting from a combination of the object beam and of the reference beam; and a demodulation device, the system being configured to, during a measurement phase: apply to the modulation signal a first pseudo-random sequence of jumps of a parameter selected among the phase, the frequency, and the amplitude; and simultaneously apply to the modulated portion of the object beam a second pseudo-random sequence of jumps of said parameter, wherein the first and second sequences of jumps of said parameter are non-correlated.

An optical receiver includes: a first combiner configured to output first combined light by combining local light of first polarization and signal light of second polarization; a converter configured to convert the first combined light to a first electric signal; a converter configured to covert a component of the first combined light that has passed through a first polarizer to a second electric signal; a converter configured to convert a component of the first combined light that has passed through a wave plate and a polarizer to a third electric signal; a divider configured to output a fourth electric signal and a fifth electric signal by branching the first electric signal; subtractors configured to subtract the fourth electric signal from the second electric signal and the fifth electric signal from the third electric signal.