An object is to be capable of housing an optical fiber that connects between components not to exceed a bending limit of the optical fiber in a housing of a pluggable optical module. A pluggable electric connector (11) is configured to be insertable into and removable from an optical communication apparatus (93). An optical output module (12) outputs an optical signal (LS1) and a local oscillation light (LO). An optical reception module (13) outputs a communication data signal (DAT) generated by demodulating using the local oscillation light (LO). A pluggable optical receptor (15) is configured in such a manner that optical fibers are insertable thereinto and removable therefrom. A first optical fiber (F11) is connected between the optical output module (12) and the pluggable optical receptor (15). A second optical fiber (F12) is connected between the optical output module (12) and the optical reception module (13). A third optical fiber (F13) is connected between the optical reception module (13) and the pluggable optical receptor (15). Optical fiber housing means winds extra lengths of the first to third optical fibers (F11 to F13) around a guide.

Devices, systems and methods for encoding information using optical components are described. Information associated with a first optical signal (e.g., an optical pump) is encoded onto the phase of a second optical signal (e.g., an optical probe) using cross phase modulation (XPM) in a non-linear optical medium. The optical signals are multiplexed together into the nonlinear optical medium. The probe experiences a modified index of refraction as it propagates through the medium and thus accumulates a phase change proportional to the intensity of the pump. The disclosed devices can be incorporated into larger components and systems for various applications such as scientific diagnostics, radar, remote sensing, wireless communications, and quantum computing that can benefit from encoding and generation of low noise, high resolution signals. Examples of the encoded information includes intrinsic noise from the optical source, or others signals of interest, such as electrical, optical, X-ray, or high-energy particle signals.

A digital coherent receiver includes: an adaptive equalizer configured to execute, using a first tap coefficient, adaptive equalization processing on a digital signal that corresponds to a signal; a first coefficient updating unit configured to update the first tap coefficient based on the digital signal on which the adaptive equalization processing has not been executed, the digital signal on which the adaptive equalization processing has been executed, and a first step size; a second coefficient updating unit configured to update a second tap coefficient based on the digital signal on which the adaptive equalization processing has not been executed, the digital signal on which the adaptive equalization processing has been executed, and a second step size; and a control unit configured to detect a fluctuation speed of a state of polarization of the digital signal based on the second tap coefficient, and change the first tap coefficient to the updated second tap coefficient if it is determined that the fluctuation speed is higher than or equal to a speed threshold.

A laser interferometer includes a light source that emits first laser light, an optical modulator that includes a vibrator and modulates the first laser light by using the vibrator to generate second laser light including a modulated signal, a photodetector that receives interference light between third laser light including a sample signal generated by reflecting the first laser light on an object and the second laser light to output a light reception signal, a demodulation circuit that demodulates the sample signal from the light reception signal based on a reference signal, and a signal generator that outputs the reference signal input to the demodulation circuit and outputs a drive signal input to the optical modulator, in which Vd/Vr<10, where Vr is a voltage of the reference signal and Vd is a voltage of the drive signal.

A laser interferometer includes a light source that emits first laser light, an optical modulator that includes a vibrator and modulates the first laser light by using the vibrator to generate second laser light including a modulated signal, a photodetector that receives interference light between third laser light including a sample signal generated by reflecting the first laser light on an object and the second laser light to output a light reception signal, a demodulation circuit that demodulates the sample signal from the light reception signal based on a reference signal, and a signal generator that outputs the reference signal input to the demodulation circuit and outputs a drive signal input to the optical modulator, in which Vd/Vr<10, where Vr is a voltage of the reference signal and Vd is a voltage of the drive signal.

A laser interferometer includes a light source that emits first laser light, an optical modulator that includes a vibrator and modulates the first laser light by using the vibrator to generate second laser light including a modulated signal, a photodetector that receives interference light between third laser light including a sample signal generated by reflecting the first laser light on an object and the second laser light to output a light reception signal, and a demodulation circuit that performs a demodulation process for demodulating the sample signal from the light reception signal, and the demodulation circuit intermittently performs the demodulation process.

A laser interferometer includes a light source that emits first laser light, an optical modulator that includes a vibrator and modulates the first laser light by using the vibrator to generate second laser light including a modulated signal, a photodetector that receives interference light between third laser light including a sample signal generated by reflecting the first laser light on an object and the second laser light to output a light reception signal, and a demodulation circuit that performs a demodulation process for demodulating the sample signal from the light reception signal, and the demodulation circuit intermittently performs the demodulation process.

A technique is described to deterministically tune the emission frequency of individual semiconductor photon sources, for example quantum dots. A focused laser is directed at a film of material that changes form when heated (for example, a phase change material that undergoes change between crystal and amorphous forms) overlaid on a photonic membrane that includes the photon sources. The laser causes a localized change in form in the film, resulting in a change in emission frequency of a photon source.

A method for generating a control signal, having at least one frequency component, for an acousto-optical element, from one frequency spectrum having the at least one frequency, or from multiple frequency spectra which together have the at least one frequency, includes the step of obtaining, from the one frequency spectrum or from the multiple frequency spectra, one transmit signal in the time domain in each case via an inverse Fourier transform. The one or the multiple transmit signals are modulated via a single-sideband modulation onto a carrier signal having a carrier frequency in order to obtain one modulated signal in each case. The control signal is obtained as a real part of the one modulated signal or as a consolidation of the real parts of the multiple modulated signals.

A method for generating a control signal, having at least one frequency component, for an acousto-optical element, from one frequency spectrum having the at least one frequency, or from multiple frequency spectra which together have the at least one frequency, includes the step of obtaining, from the one frequency spectrum or from the multiple frequency spectra, one transmit signal in the time domain in each case via an inverse Fourier transform. The one or the multiple transmit signals are modulated via a single-sideband modulation onto a carrier signal having a carrier frequency in order to obtain one modulated signal in each case. The control signal is obtained as a real part of the one modulated signal or as a consolidation of the real parts of the multiple modulated signals.