A method of, and module for, converting position or momentum correlation of correlated photon pairs to a polarization entangled photon pair, and a source for polarization entangled photon pairs. The method comprises a conversion step of separating the correlated photon pairs into first and second groups based on their generated position at the crystal (position correlation) or their direction about the propagation axis (momentum correlation) and rotating a polarization of the first correlated photon pair group such that the polarization of the first correlated pair group is at 90 degrees relative to the polarization of the second correlated photon pair group; and a combining step of combining the first and second correlated photon pairs such that at least respective portions of respective spatial distributions of the first and second photon pair groups overlap with negligible wavelength dependent phase difference.

A quantum communication system that includes a multiphoton entanglement generator, a plurality of photon detector units, and a plurality of optical fiber links. The plurality of photon detector units include a first photon detector unit and a second photon detector unit. The multiphoton entanglement generator is structurally configured to output more than two entangled photons. The plurality of optical fiber links comprise a first optical fiber link optically coupled to the multiphoton entanglement generator and disposed between the multiphoton entanglement generator and the first photon detector unit. The plurality of optical fiber links comprise a second optical fiber link optically coupled to the multiphoton entanglement generator and disposed between the multiphoton entanglement generator and the second photon detector unit. Further, at least one of the plurality of optical fiber links has a core, a cladding, and a scattering region having a plurality of scattering structures.

A quantum communication system that includes a multiphoton entanglement generator, a plurality of photon detector units, and a plurality of optical fiber links. The plurality of photon detector units include a first photon detector unit and a second photon detector unit. The multiphoton entanglement generator is structurally configured to output more than two entangled photons. The plurality of optical fiber links comprise a first optical fiber link optically coupled to the multiphoton entanglement generator and disposed between the multiphoton entanglement generator and the first photon detector unit. The plurality of optical fiber links comprise a second optical fiber link optically coupled to the multiphoton entanglement generator and disposed between the multiphoton entanglement generator and the second photon detector unit. Further, at least one of the plurality of optical fiber links has a core, a cladding, and a scattering region having a plurality of scattering structures.

To provide a light source device for a fiber optic gyroscope capable of broadening the bandwidth of the laser light and improving stability of a scale factor.

A light source device for a fiber optic gyroscope configured to drive a fiber optic gyroscope includes: a laser light source 10, a stabilizing part 20, and a bandwidth broadening part 30. The laser light source 10 emits a laser light of a predetermined frequency. The stabilizing part 20 stabilizes the predetermined frequency of the laser light emitted from the laser light source 10. The bandwidth broadening part 30 makes the laser light stabilized by the stabilizing part 20 into a light having a continuous broadband spectrum.

To provide a light source device for a fiber optic gyroscope capable of broadening the bandwidth of the laser light and improving stability of a scale factor.

A light source device for a fiber optic gyroscope configured to drive a fiber optic gyroscope includes: a laser light source 10, a stabilizing part 20, and a bandwidth broadening part 30. The laser light source 10 emits a laser light of a predetermined frequency. The stabilizing part 20 stabilizes the predetermined frequency of the laser light emitted from the laser light source 10. The bandwidth broadening part 30 makes the laser light stabilized by the stabilizing part 20 into a light having a continuous broadband spectrum.

Disclosed is an apparatus for single-pixel imaging using quantum light, the apparatus including: a light source which generates a photon pair through spontaneously parametric down conversion of a non-linear crystal and splits the photon pair into an idler photon of first polarized light and a signal photon of second polarized light; a signal processing unit which aligns the signal photon with the first polarized light and modulates the signal photon with a pattern of a spatial light modulator, and sends the modulated signal photon to a target; and a signal detecting unit which simultaneously measures signal photons collected after an interaction of the idler photon and the target to obtain an image.

Disclosed is an apparatus for single-pixel imaging using quantum light, the apparatus including: a light source which generates a photon pair through spontaneously parametric down conversion of a non-linear crystal and splits the photon pair into an idler photon of first polarized light and a signal photon of second polarized light; a signal processing unit which aligns the signal photon with the first polarized light and modulates the signal photon with a pattern of a spatial light modulator, and sends the modulated signal photon to a target; and a signal detecting unit which simultaneously measures signal photons collected after an interaction of the idler photon and the target to obtain an image.

An optical waveguide structure comprising a nonlinear optical waveguide, a central region, a first side region, and a second side region. The central region is located within the nonlinear optical waveguide, wherein the central region comprises a nonlinear optical material. The first side region is on a first side of the central region and the second side region is on a second side of the central region. The nonlinear optical material comprising the central region has a first nonlinear coefficient that is larger than a second nonlinear coefficient of a second material comprising the first side region and the second side region.

An optical waveguide structure comprising a nonlinear optical waveguide, a central region, a first side region, and a second side region. The central region is located within the nonlinear optical waveguide, wherein the central region comprises a nonlinear optical material. The first side region is on a first side of the central region and the second side region is on a second side of the central region. The nonlinear optical material comprising the central region has a first nonlinear coefficient that is larger than a second nonlinear coefficient of a second material comprising the first side region and the second side region.

In one aspect, a device is disclosed that includes one or more input ports structured to receive a pumping light at a pumping wavelength and a signal light at a signal wavelength, and one or more output ports structured to output light including an amplified signal light at the signal wavelength and a second harmonic idler light. The device includes a nonlinear optical material to mix the pumping light and the signal light and to cause nonlinear conversion of the pumping light into the amplified signal light and generate an idler light at an idler wavelength. The nonlinear optical material is further structured to convert the idler light into the second harmonic idler light which eliminates the idler light at the one or more output ports and prevents back-conversion of the amplified signal light and idler light to the pumping wavelength.