Broad Frequency Shift of Parametric Processes in Epsilon-Near-Zero Time-Varying Media

Vincenzo Bruno, Stefano Vezzoli, Clayton DeVault, Enrico Carnemolla, Marcello Ferrera, Alexandra Boltasseva, Vladimir M. Shalaev, Daniele Faccio, Matteo Clerici
2020 Applied Sciences  
The ultrafast changes of material properties induced by short laser pulses can lead to a frequency shift of reflected and transmitted radiation. Recent reports highlight how such a frequency shift is enhanced in spectral regions where the material features a near-zero real part of the permittivity. Here, we investigate the frequency shift for fields generated by four-wave mixing. In our experiment, we observed a frequency shift of more than 60 nm (compared to the pulse width of ∼40 nm) in the
more » ... of ∼40 nm) in the phase conjugated radiation generated by a 500 nm aluminium-doped zinc oxide (AZO) film pumped close to the epsilon-near-zero wavelength. Our results indicate applications of time-varying media for nonlinear optics and frequency conversion.
doi:10.3390/app10041318 fatcat:pjhsaqplwbgynjjo6zdz64adsy