Measurement of the refractive index of ADP and KDP crystals in the infrared range by parametric scattering of light

Nonlinear Dielectric Nanoresonators and Metasurfaces: Toward Efficient Generation of Entangled Photons

“…Among the nonlinear optical structures used for controlling the properties of generated photon pairs are suitably cut bulk crystals, waveguides, and optical fibers, as well as resonators. [ 6,7,11–15 ] In the past, control of the polarization, spectrum, spatial composition, and degree of entanglement were demonstrated based on the principles of tailoring propagating fields within nonlinear systems that were much longer than the wavelength of light. [ 9,16 ]…”

“…SPDC is possible in materials with broken inversion symmetry featuring a second‐order nonlinearity. [ 6 ] In this parametric three‐wave mixing process, pump photons spontaneously decay into pairs of signal and idler photons. In materials with inversion symmetry, photon pairs can be generated SFWM where now two pump photons are converted into photon pairs.…”

“…Among the nonlinear optical structures used for controlling the properties of generated photon pairs are suitably cut bulk crystals, waveguides, and optical fibers, as well as resonators. [6,7,[11][12][13][14][15] In the past, control of the polarization, spectrum, spatial composition, and degree of entanglement were demonstrated based on the principles of tailoring propagating fields within nonlinear systems that were much longer than the wavelength of light. [9,16] In the last years, a different paradigm for controlling both linear and nonlinear light-matter interaction has seen a rapid development: Resonant dielectric nanostructures and metasurfaces have demonstrated remarkable capabilities of controlling virtually every parameter of the electromagnetic field via carefully engineered geometrical resonances at the subwavelength scale.…”

Gaussian functions are optimal for waveguided nonlinear-quantum-optical processes

“…χ (2) , nonlinear processes. The most popular χ (2) process, spontaneous parametric down conversion (SPDC) [19,26], generates photon pairs that can be used directly, or can be converted into heralded single photons [27][28][29][30]. χ (2) interactions can also be used in frequency conversion (FC) [31,32] to alter the spectral properties of input single photons.…”

Cascaded coherent Stokes Raman scattering in LiNbO3:Mg crystals under excitation of small polarons and phonon polaritons

“…The results of the CSRS by excited polaritons are compared with the data on ε 0 ω and ε 00 ω , obtained by the spontaneous light scattering by unexcited polaritons. 4,23 Polarons in LiNbO 3 :Mg are induced by the chemical reduction; their characteristics have been studied previously. 17,24 -29 EXPERIMENTAL Two samples were cut from the same bulk LiNbO 3 :Mg crystal, grown by the Czochralski method.…”