A nonlinear converter may comprise: alternating layers of a dielectric material and a metal material; a first refractive index of the nonlinear converter for a first wavelength (i.e., input wavelength or pump wavelength) between 207 nm and 237 nm, the first refractive index being less than 0.5, the first refractive index corresponding to metal fill ratio; and a second refractive index of the nonlinear converter for a second wavelength (i.e., output wavelength or SHG wavelength), the second wavelength being approximately double the first wavelength, the second refractive index corresponding to the metal fill ratio.

A nonlinear converter may comprise: alternating layers of a dielectric material and a metal material; a first refractive index of the nonlinear converter for a first wavelength (i.e., input wavelength or pump wavelength) between 207 nm and 237 nm, the first refractive index being less than 0.5, the first refractive index corresponding to metal fill ratio; and a second refractive index of the nonlinear converter for a second wavelength (i.e., output wavelength or SHG wavelength), the second wavelength being approximately double the first wavelength, the second refractive index corresponding to the metal fill ratio.

Provided are a nonlinear polarization filtering method, device, and apparatus. The device comprises a pump source, a coupler, a birefringent medium, and several polarizers; wherein the pump source is applied to output a pump laser, so as to make a photo-induced birefringence effect occur at the birefringent medium; the polarizer is applied to polarize a signal light according to a preset polarizing angle; and the coupler is applied to couple the pump laser and the signal light into the birefringent medium, wherein an angle except 0° exists between the birefringent medium and the preset polarizing angle of the polarizer.

A quantum source includes: a quantum source generator dividing a pump beam into a plurality of channels and generating a plurality of signals and a plurality of idlers using nonlinear crystals respectively located optical paths of the plurality of channels; and an entangled photon pair combiner outputting an enhanced signal by combining the plurality of signals and outputting an enhanced idler by combining the plurality of idlers.

A quantum source includes: a quantum source generator dividing a pump beam into a plurality of channels and generating a plurality of signals and a plurality of idlers using nonlinear crystals respectively located optical paths of the plurality of channels; and an entangled photon pair combiner outputting an enhanced signal by combining the plurality of signals and outputting an enhanced idler by combining the plurality of idlers.

A method of making an optical device including forming a plurality of holes with varying radii milled vertically into a film, wherein said holes form a pattern. The radius of each hole determines an effective refractive index for said hole. The effective refractive index modifies a phase and an intensity of an incoming electromagnetic radiation as the radiation propagates through said hole. The device is configured to be operating equally for each linearly polarized radiation simultaneously, wherein the each linearly polarized radiation is normally incident on the device.

The present invention relates to a generation device and a generation method of terahertz waves with orbital angular momentum. The generation device comprises a first laser and a second laser; the first laser radiates a first laser beam; the second laser radiates a second laser beam; and the frequency difference between the first laser beam and the second laser beam is within a terahertz wave band. The generation device further comprises an orbital angular momentum generator, a beam combiner and a terahertz radiation generator; the first laser beam passes through the orbital angular momentum generator to generate the first laser beam with the orbital angular momentum; after the first laser beam with the orbital angular momentum and a second laser beam are combined to form a combined beam, the combined beam reaches a terahertz radiation transmitter; the terahertz radiation transmitter performs frequency mixing and filtering processing on the first laser beam A with the orbital angular momentum and the second laser beam B to generate terahertz waves with the orbital angular momentum. Through a simple beam path design, terahertz wave beams with orbital angular momentum, which are low in consumption and high in efficiency, can be obtained.

An optical parametric oscillator (OPO) system comprises an optical waveguide including a hollow core containing a fluid, wherein the optical waveguide is configured to receive pump light and to convert the pump light into signal light and idler light via a third order non-linear optical effect. The OPO system further comprises an optical feedback arrangement for recycling at least a portion of the signal light and/or for recycling at least a portion of the idler light in an optical cavity that includes the optical waveguide. The OPO system may be used, in particular though not exclusively, in metrology, gas and solid-state spectroscopy, laser-assisted manufacturing, semiconductor technology, biomedicine, healthcare, and scientific laboratory use.

The present invention relates to a generation device and a generation method of terahertz waves with orbital angular momentum. The generation device comprises a first laser and a second laser; the first laser radiates a first laser beam; the second laser radiates a second laser beam; and the frequency difference between the first laser beam and the second laser beam is within a terahertz wave band. The generation device further comprises an orbital angular momentum generator, a beam combiner and a terahertz radiation generator; the first laser beam passes through the orbital angular momentum generator to generate the first laser beam with the orbital angular momentum; after the first laser beam with the orbital angular momentum and a second laser beam are combined to form a combined beam, the combined beam reaches a terahertz radiation transmitter; the terahertz radiation transmitter performs frequency mixing and filtering processing on the first laser beam A with the orbital angular momentum and the second laser beam B to generate terahertz waves with the orbital angular momentum. Through a simple beam path design, terahertz wave beams with orbital angular momentum, which are low in consumption and high in efficiency, can be obtained.

A method of making an optical device including forming a plurality of holes with varying radii milled vertically into a film, wherein said holes form a pattern. The radius of each hole determines an effective refractive index for said hole. The effective refractive index modifies a phase and an intensity of an incoming electromagnetic radiation as the radiation propagates through said hole. The device is configured to be operating equally for each linearly polarized radiation simultaneously, wherein the each linearly polarized radiation is normally incident on the device.