Nonlinear response in a material increases with its index of refraction as n4. Commonly, n ~ 1 so that diffraction, dispersion, and chromatic walk-off limit nonlinear scattering. Ferroelectric crystals with a periodic 3D polarization structure overcome some of these constraints through versatile Cherenkov and quasi-phase-matching mechanisms. Threedimensional self-structuring can also lead to a giant optical refraction. Here, we perform second-harmonic-generation experiments in KTN:Li in conditions of giant broadband refraction. Enhanced response causes wavelength conversion to occur in the form of bulk Cherenkov radiation without diffraction and chromatic walk-off, even in the presence of strong wave-vector mismatch and highly focused beams. The process occurs with a wide spectral acceptance of more than 100 nm in the near infrared spectrum, an ultra-wide angular acceptance of up to ±40∘, with no polarization selectivity, and can be tuned to allow bulk supercontinuum generation. Results pave the way to highly efficient and adaptable nonlinear optical devices with the promise of single-photon-to-single-photon nonlinear optics.

Falsi, L., Tartara, L., Dimei, F., Flammini, M., Parravicini, J., Pierangeli, D., et al. (2020). Constraint-free wavelength conversion supported by giant optical refraction in a 3D perovskite supercrystal. COMMUNICATIONS MATERIALS, 1(1) [10.1038/s43246-020-00077-z].

Constraint-free wavelength conversion supported by giant optical refraction in a 3D perovskite supercrystal

J. Parravicini;
2020

Abstract

Nonlinear response in a material increases with its index of refraction as n4. Commonly, n ~ 1 so that diffraction, dispersion, and chromatic walk-off limit nonlinear scattering. Ferroelectric crystals with a periodic 3D polarization structure overcome some of these constraints through versatile Cherenkov and quasi-phase-matching mechanisms. Threedimensional self-structuring can also lead to a giant optical refraction. Here, we perform second-harmonic-generation experiments in KTN:Li in conditions of giant broadband refraction. Enhanced response causes wavelength conversion to occur in the form of bulk Cherenkov radiation without diffraction and chromatic walk-off, even in the presence of strong wave-vector mismatch and highly focused beams. The process occurs with a wide spectral acceptance of more than 100 nm in the near infrared spectrum, an ultra-wide angular acceptance of up to ±40∘, with no polarization selectivity, and can be tuned to allow bulk supercontinuum generation. Results pave the way to highly efficient and adaptable nonlinear optical devices with the promise of single-photon-to-single-photon nonlinear optics.
Articolo in rivista - Articolo scientifico
SHG; second harmonic generation; disordered materials; perovskite;
English
22-ott-2020
2020
1
1
76
open
Falsi, L., Tartara, L., Dimei, F., Flammini, M., Parravicini, J., Pierangeli, D., et al. (2020). Constraint-free wavelength conversion supported by giant optical refraction in a 3D perovskite supercrystal. COMMUNICATIONS MATERIALS, 1(1) [10.1038/s43246-020-00077-z].
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/10281/289093
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