An optical modulator connected to a first optical fiber and a second optical fiber arranged in parallel includes an optical-path changing unit that redirects light emerging from a tip of the first optical fiber toward a tip of the second optical fiber and an optical modulation chip that modulates the light redirected by the optical-path changing unit and outputs a light beam obtained by modulating the light to a tip of the second optical fiber.

A quantum computing system, method and computer readable medium involve a vacuum enclosure for sustaining a vacuum below 10.sup.?3 millibar, optical resonators tuned to a resonance of an alkali atom, and a trapping laser for maintaining the alkali atom within a mode of the optical resonators. An atom excitation laser induces photon emissions, a plurality of waveguides couple photons to and from the optical resonators, and a plurality of detectors detect a presence or absence of an atom-resonator coupling. A processor receives output signals from the detectors and controls optical switches for switching between two or more of the plurality of waveguides.

Described herein is a wavelength selective switch (100), comprising an input array (102) of optical fibers. The array (102) comprises two or more columns of fibers that are spatially offset in one or both of a switching dimension or a dispersive dimension of the wavelength selective switch (100). Each column (102A, 102B) of fibers is adapted to project respective optical beams. A switching engine (112) is positioned to receive the optical beams and apply an angular switching to the beams to direct the beams to respective output fibers. The optical beams are encoded at respective angles or polarization states such that each column of optical beams is incident onto a different region of the switching engine (112).

A method for controlling the splitting ratio of an input optical signal to one or more output ports is described. The splitting ratio of a fiber-coupled signal in the communications band is controlled using cross phase modulation from a pump signal in the 980-1090 nm band. This design allows the nonlinear fiber in which the cross phase modulation occurs to be standard single mode fiber having a zero dispersion wavelength between 1250 and 1350 nm, such as SMF-28e fiber, which helps to maintain the lowest possible loss and a low cost while still allowing for power efficient interactions with signal wavelengths in the technologically important 1520-1610 nm band. The design is compatible with low insertion loss, narrow switching windows, and low added noise. The location of the pump pulse can be controlled allowing for the location of an input pulse to be determined.

A light control system is provided with a spatial light modulator of a liquid-crystal type, an input unit, and a controller. The input unit is configured to input a light to the spatial light modulator. The controller is configured to cause the spatial light modulator to function as a diffraction grating by electrically controlling the spatial light modulator. The controller is configured to change a path of a diffracted light from the spatial light modulator corresponding to the light input from the input unit by changing a shape of the diffraction grating.

An optical modulator connected to a first optical fiber and a second optical fiber arranged in parallel includes an optical-path changing unit that redirects light emerging from a tip of the first optical fiber toward a tip of the second optical fiber and an optical modulation chip that modulates the light redirected by the optical-path changing unit and outputs a light beam obtained by modulating the light to a tip of the second optical fiber.

A quantum computing system, method and computer readable medium involve a vacuum chamber, an atom source input associated with the vacuum chamber, a Photonic Integrated Circuit (PIC) having an interaction region configured to interact with an atom from the atom source, a coupling location for atom positioning, a trapping laser for trapping the atom in the coupling location, an excitation laser for manipulating an electronic state or a nuclear state of the atom, a waveguide for guiding input light to the coupling location, and an output channel for directing quantum light generated at the coupling location, out of the vacuum chamber as a resource for quantum computing. The coupling location is associated with the PIC, and the interaction region of the PIC is arranged for at least partial exposure to the vacuum.

A quantum computing system, method and computer readable medium involve a vacuum enclosure for sustaining a vacuum below 10.sup.3 millibar, optical resonators tuned to a resonance of an alkali atom, and a trapping laser for maintaining the alkali atom within a mode of the optical resonators. An atom excitation laser induces photon emissions, a plurality of waveguides couple photons to and from the optical resonators, and a plurality of detectors detect a presence or absence of an atom-resonator coupling. A processor receives output signals from the detectors and controls optical switches for switching between two or more of the plurality of waveguides.

Described herein is a wavelength selective switch (100), comprising an input array (102) of optical fibers. The array (102) comprises two or more columns of fibers that are spatially offset in one or both of a switching dimension or a dispersive dimension of the wavelength selective switch (100). Each column (102A, 102B) of fibers is adapted to project respective optical beams. A switching engine (112) is positioned to receive the optical beams and apply an angular switching to the beams to direct the beams to respective output fibers. The optical beams are encoded at respective angles or polarization states such that each column of optical beams is incident onto a different region of the switching engine (112).

The present invention provides an efficient quantum memory for storing a quantum state of light, such as a photon, for a temporary period of time in a fibre-integrated optical cavity and then recall the quantum state of light and quantum information at a later time with a high probability of success. The present invention uses a nonlinear optical switching mechanism to modify at least one property of the quantum light, or cavity, to trap the quantum light in the optical cavity. Subsequent application of the nonlinear optical switching mechanism switches at least one property of the stored quantum light, or cavity, to release the quantum light from the optical cavity. The present invention also provides quasi-deterministic single-photon generation by temporal multiplexing of a photon pair source integrated within the cavity.