Open AccessVisible photon generation via four-wave mixing in near-infrared near-zero-index thin films
Author(s) -
Enrico Giuseppe Carnemolla,
Wallace Jaffray,
Matteo Clerici,
Lucia Caspani,
Daniele Faccio,
Fabio Biancalana,
Clayton DeVault,
Vladimir M. Shalaev,
Alexandra Boltasseva,
Marcello Ferrera
Publication year - 2021
Publication title -
optics letters/optics index
Language(s) - Italian
Resource type - Journals
SCImago Journal Rank - 1.524
H-Index - 272
eISSN - 1071-2763
pISSN - 0146-9592
DOI - 10.1364/ol.433834
Subject(s) - optics , four wave mixing , materials science , refractive index , wavelength , optoelectronics , near infrared spectroscopy , signal (programming language) , visible spectrum , thin film , mixing (physics) , nonlinear optics , physics , laser , quantum mechanics , computer science , programming language , nanotechnology
Optical nonlinearities can be strongly enhanced by operating in the so-called near-zero-index (NZI) regime, where the real part of the refractive index of the system under investigation approaches zero. Here we experimentally demonstrate semi-degenerate four-wave mixing (FWM) in aluminum zinc oxide thin films generating radiation tunable in the visible spectral region, where the material is highly transparent. To this end, we employed an intense pump (787 nm) and a seed tunable in the NIR window (1100-1500 nm) to generate a visible idler wave (530-620 nm). Experiments show enhancement of the frequency conversion efficiency with a maximum of 2% and a signal-to-pump detuning of 360 nm. Effective idler wavelength tuning has also been demonstrated by operating on the temporal delay between the pump and signal.