In an optical network system: control light is generated by optical modulation based on a modulated data signal which is generated by modulation of a carrier signal with a data signal; and the control light is optically combined with an optical carrier which is to propagate through a nonlinear optical medium, so as to cause cross phase modulation of the optical carrier with the control light in the nonlinear optical medium.

A waveguide optical gyroscope (WOG) is disclosed. One WOG may comprise an amplified spontaneous emission (ASE) source, a sensor comprising a waveguide loop disposed in a first cladding material interposed between layers of at least a second cladding material having an index of refraction lower than an index of refraction of the first cladding material, wherein the sensor is configured to receive an output signal of the ASE source, and a pump source configured to pump the first cladding material with an in-plane pump signal.

An arrangement for reducing the number of amplifier pumps required to energize gain sections in fiber lasers which incorporate nonlinear amplified loop mirrors.

An optical apparatus includes a main body, a reflecting object lens pivotally connected to the main body and a cover pivotally connected to the reflecting object lens. The reflecting object lens is rotatable with respect to the main body within a first angle, and the cover is rotatable with respect to the reflecting object lens within a second angle.

A photonic device which is configured to implement a recurrent neural network via reservoir computing is provided. The device includes a feed portion which mixes an input signal with previously generated and controllably attenuated portions of an output signal. The device further includes one or more propagating stages coupled to the feed portion. Each propagating stage propagates signals through a loop in both clockwise and counterclockwise directions, for example to be affected by nonlinear elements. The arrangement of the photonic device causes a nonlinear activation function to be realized by the propagating stages. The nonlinear activation function may be adjustable by adjusting various controllable elements in the device.

A fiber optic gyroscope includes an optical fiber coil, at least one optical circuit, and at least one optical gate. The at least one optical circuit is configured to receive input optical signals generated by at least one optical source, to split each input optical signal into first and second optical signals, to phase modulate one or both of the first and second optical signals, to transmit the first and second optical signals to the optical fiber coil such that the first and second optical signals counterpropagate through the optical fiber coil, to receive the first and second optical signals after counterpropagating through the optical fiber coil, to combine the first and second optical signals after counterpropagating through the optical fiber coil, and to transmit the combined first and second optical signals to at least one photodetector. The at least one optical gate is configured to controllably time modulate the input optical signals and/or the first and second optical signals prior to being combined, said time modulating synchronized with said phase modulating.

A multi-wavelength entangled photon pair generation device includes: a multi-mode pump laser that radiates a broadband pump laser beam in an ultraviolet wavelength range including multiple Gaussian-distributed wavelengths; a nonlinear crystal that generates a multi-wavelength de-multiplexed entangled photon pair in a near-infrared wavelength range including multiple wavelength components corresponding to multiple Gaussian-distributed wavelengths of the broadband pump laser beam, respectively; a temperature controller that adjusts a temperature of the nonlinear crystal; and an output optical system that filters out the broadband pump laser beam from light output through the nonlinear crystal and passes the multi-wavelength de-multiplexed entangled photon pair.

An interferometric module, constructed in single pentagonal block to produce high quality, robust, low cost entangled-photon sources enabling polarization entanglement swapping. The compact block forms a generic platform that facilitates a comprehensive integration of optical components while allowing for quick optical alignments. Phase-stability of the self-balanced Sagnac interferometer is harnessed to offer a highly stable performance at room temperature and under sever operating conditions. High-quality entanglement is inherently achieved by equalizing two interferometric optical paths from counter-propagating photons. A periodically poled nonlinear crystal is placed between two half-wave plates, which also serve to correct the polarization states of the photons. The result is compensation-free and plug-and-play entangled-photon sources for quantum routers, distributed quantum sensing and quantum telecommunication. Wavelengths and generation rate of photon pairs are realized via the hosted crystal. Energy and polarization entanglement, and hyperentanglement can be remotely set by rotating the polarization state of the pump laser diode.

A fiber optic gyroscope includes an optical fiber coil, at least one optical circuit, and at least one optical gate. The at least one optical circuit is configured to receive input optical signals generated by at least one optical source, to split each input optical signal into first and second optical signals, to phase modulate one or both of the first and second optical signals, to transmit the first and second optical signals to the optical fiber coil such that the first and second optical signals counterpropagate through the optical fiber coil, to receive the first and second optical signals after counterpropagating through the optical fiber coil, to combine the first and second optical signals after counterpropagating through the optical fiber coil, and to transmit the combined first and second optical signals to at least one photodetector. The at least one optical gate is configured to controllably time modulate the input optical signals and/or the first and second optical signals prior to being combined, said time modulating synchronized with said phase modulating.