Efficient harmonic light generation can be achieved with ultrathin films by coupling an incident pump wave to an epsilon-near-zero (ENZ) mode of the thin film. As an example, efficient third harmonic generation from an indium tin oxide nanofilm (λ/42 thick) on a glass substrate for a pump wavelength of 1.4 μm was demonstrated. A conversion efficiency of 3.3×10.sup.−6 was achieved by exploiting the field enhancement properties of the ENZ mode with an enhancement factor of 200. This nanoscale frequency conversion method is applicable to other plasmonic materials and reststrahlen materials in proximity of the longitudinal optical phonon frequencies.

A graphene structure includes one or more graphene layers. The graphene layers allow for microwave squeezing with gains up to 24 dB over a wide bandwidth.

A graphene structure includes one or more graphene layers. The graphene layers allow for microwave squeezing with gains up to 24 dB over a wide bandwidth.

A method for extending and enhancing bright coherent high-order harmonic generation into the VUV-EUV-X-ray regions of the spectrum involves a way of accomplishing phase matching or effective phase matching of extreme upconversion of laser light at high conversion efficiency, approaching 10.sup.−3 in some spectral regions, and at significantly higher photon energies in a waveguide geometry, in a self-guiding geometry, a gas cell, or a loosely focusing geometry, containing nonlinear medium. The extension and enhancement of the coherent VUV, EUV, X-ray emission to high photon energies relies on using VUV-UV-VIS lasers of shorter wavelength. This leads to enhancement of macroscopic phase matching parameters due to stronger contribution of linear and nonlinear dispersion of both atoms and ions, combined with a strong microscopic single-atom yield.

Embodiments of the present invention provide systems and methods to robustly inter-convert between polarization-entangled photon pairs and time-entangled photon pairs, such that produced polarization-entangled photons pairs can be converted into time-entangled photon pairs, stored as time-entangled photon pairs to preserve the entanglement for longer periods of time, and then converted back to polarization-entangled photon pairs when ready for manipulation, processing, and measurement by a quantum application.

A method of generating THz radiation includes the steps of generating optical input radiation with an input radiation source device (10), irradiating a first conversion crystal device (30) with the optical input radiation, wherein the first conversion crystal device (30) is arranged in a single pass configuration, and generating the THz radiation having a THz frequency in the first conversion crystal device (30) in response to the optical input radiation by an optical-to-THz-conversion process, wherein a multi-line frequency spectrum is provided by the optical input radiation in the first conversion crystal device (30), and the optical-to-THz-conversion process includes cascaded difference frequency generation using the multi-line frequency spectrum. Furthermore, a THz source apparatus being configured for generating THz radiation and applications thereof are described.

The present application discloses a nonlinear optical crystal material, preparation method and application of the nonlinear optical crystal material. The nonlinear optical crystal material has an excellent infrared nonlinear optical performance, whose frequency-doubling intensity can reach 9.3 times of AgGaS.sub.2 with the same particle size, and it meets type-I phase matching; and its laser damage threshold can reach 7.5 times of AgGaS.sub.2 with the same particle size. The nonlinear optical crystal material has important application value in the frequency-converters which can be used for frequency doubling, sum frequency, difference frequency, optical parametric oscillation of laser in mid and far infrared waveband, and the like.

This disclosure provides an optical parametric oscillator, comprising, in a light path, a first lens, a laser crystal, a second lens, a nonlinear optical crystal, and a third lens in this order, wherein an optical parametric oscillation chamber is formed between the second lens and the third lens, and the nonlinear optical crystal is a monoclinic Ga.sub.2S.sub.3 crystal, the space group of the monoclinic Ga.sub.2S.sub.3 crystal is Cc, and the unit cell parameters are a=11.1 Å, b=6.4 Å, c=7.0 Å, α=90°, β=121°, γ=90°, and Z=4.

This disclosure provides an optical parametric oscillator, comprising, in a light path, a first lens, a laser crystal, a second lens, a nonlinear optical crystal, and a third lens in this order, wherein an optical parametric oscillation chamber is formed between the second lens and the third lens, and the nonlinear optical crystal is a monoclinic Ga.sub.2S.sub.3 crystal, the space group of the monoclinic Ga.sub.2S.sub.3 crystal is Cc, and the unit cell parameters are a=11.1 Å, b=6.4 Å, c=7.0 Å, α=90°, β=121°, γ=90°, and Z=4.

Optical component (10) for modulating light field (1) incident thereon, particularly amplitude and/or phase in dependency on intensity (I) thereof, includes stack (11) of refractive layers (12, 13) on substrate (14), made of materials having third-order nonlinearity, and having alternatingly varying refractive indices (n), including linear contribution (n.sub.0) and non-linear contribution (n.sub.2), and determining reflectance and transmittance spectra of the optical component, wherein refractive layers (12, 13) are configured such that reflectance and transmittance of the optical component have a Kerr effect based dependency on intensity (I) of the incident light field with n=n.sub.0+I.Math.n.sub.2, and refractive layers (12, 13) are made of at least one of dielectric and semiconductor layers, wherein non-linear contribution (n.sub.2) is below 10.sup.−12 cm.sup.2/W. A resonator device including the optical component, a method of modulating a light field using the optical component and a method of manufacturing the optical component are described.