An optical waveguide structure comprises a nonlinear optical waveguide comprising a nonlinear optical material having a second order nonlinear coefficient that changes with a direction of light propagation. A first portion of the nonlinear optical waveguide in which a light propagating through the first portion is affected by a positive value of a second order nonlinear coefficient. A second portion of the nonlinear optical waveguide in which the light propagating through the first portion is affected by a negative value of a second order nonlinear coefficient, wherein a set of dimensions in the nonlinear optical waveguide in the first portion and the second portion is selected to cause the light to have a phase walk-off that is an odd multiple of 180 degrees.

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.

A method for reconfigurable optical signal processing. The method includes generating a first pump pulse by propagating a first input pump through a first dispersive medium, generating a first modulated signal by applying a parametric nonlinear wave mixing process on an input optical signal and the first pump pulse, generating a first transformed signal of the input optical signal by propagating the first modulated signal through a second dispersive medium, generating a multiplied signal by multiplying the first transformed signal by a Green's function, generating a second pump pulse by propagating a second input pump through a third dispersive medium, generating a second modulated signal by applying the parametric nonlinear wave mixing process on the multiplied signal utilizing the second pump pulse, and generating a second transformed signal of the multiplied signal by propagating the second modulated signal through a fourth dispersive medium.

A transmission device includes: a first wavelength conversion circuit configured to convert a wavelength band of a wavelength multiplexed signal light based on a wavelength of a second excitation light by performing four-wave mixing on the second excitation light and the wavelength multiplexed signal light inputted to a second nonlinear medium; and a second wavelength conversion circuit configured to convert the wavelength band of the wavelength multiplexed signal light based on a difference between frequencies of a third excitation light and a fourth excitation light by performing four-wave mixing on the third excitation light and the fourth excitation light and the wavelength multiplexed signal light inputted to a third nonlinear medium.

A wavelength conversion device includes a wavelength converter converts a wavelength band of a wavelength-division multiplex signal, a first wavelength filter transmits the wavelength-division multiplex signal on an input side of the wavelength converter, a second wavelength filter transmits the wavelength-division multiplex signal on an output side of the wavelength converter, and a controller controls a temperature of the wavelength converter such that a difference between a ratio of power of the wavelength-division multiplex signal which is not transmitted through the first wavelength filter on the input side to power of the wavelength-division multiplex signal which have been transmitted through the first wavelength filter on the input side and a ratio of a power of the wavelength-division multiplex signal which is not transmitted through the second wavelength filter on the output side to power of the wavelength-division multiplex signal which have been transmitted through the second wavelength filter.

A topological photonic system configured as a robust source of indistinguishable photons pairs with tunable spectral correlations. The system includes a two-dimensional silicon-photonic ring resonator array configured to implement an anomalous-quantum Hall model that exhibits topologically robust edge states. Linear dispersion of the edge states ensures efficient and robust phase matching and tunability of the spectral bandwidth of photon pairs generated via spontaneous four-wave mixing. Spectral tunability is manifested in the temporal correlations in the Hong-Ou-Mandel interference between photons. The generated photon pairs are energy-time entangled.

The invention relates to an arrangement and a method for efficient, non-linear light conversion. The object of the present invention of specifying an arrangement for efficient, non-linear light conversion, which simultaneously optimally fulfills the local conversion rate, the interaction scale, and the dispersive properties, is achieved in that the arrangement is provided in the form of a component, which comprises an optical waveguide or an optical fiber with or without cavities, wherein said arrangement consists of fiber cladding substrate or waveguide substrate (IV) with an adapted geometry, which defines the light-guiding properties of the fiber mode with designed dispersion properties (VI), and wherein the waveguide or the core carries a grown, atomically-thin layer of transition metal dichalcogenides in the form of crystallites, wherein this layer completely or partially covers the waveguide or the core.

Radiation source assemblies and methods for generating broadened radiation by spectral broadening. A radiation source assembly includes a pump source configured to emit modulated pump radiation at one or more wavelengths. The assembly further has an optical fiber configured to receive the modulated pump radiation emitted by the pump source, the optical fiber including a hollow core extending along at least part of a length of the fiber. The hollow core is configured to guide the received radiation during propagation through the fiber. The radiation emitted by the pump source includes first radiation at a pump wavelength, and the pump source is configured to modulate the first radiation for stimulating spectral broadening in the optical fiber.

A coherent anti-stokes Raman scattering apparatus for imaging a sample includes an optical output; an optical source arranged to generate a first optical signal at a first wavelength; and a nonlinear element arranged to receive the first optical signal, where the nonlinear element is arranged to cause the first optical signal to undergo four-wave mixing on transmission through the nonlinear element such that a second optical signal at a second wavelength and a third optical signal at a third wavelength are generated, wherein an optical signal pair including two of the first, second and third optical signals is provided to the optical output for imaging the sample.

A photon source includes a bus waveguide, a photon source pump laser coupled to the bus waveguide and a plurality of optical resonators coupled to the bus waveguide. Each optical resonator of the plurality of optical resonators has a respective resonance line width and a respective resonance frequency, wherein a bandwidth of the resonant center frequencies of the plurality of optical resonators is greater than a bandwidth of the photon source pump laser. The bus waveguide produces photons in response to receiving laser pulses from the pump laser.