2020/08/24 by Diego M. Solís, Robert W. Boyd, Solís, Diego M. +3 · 1 citation
Engineering · Physics and Astronomy · #Applied Physics (physics.app-ph) #FOS: Physical sciences #Optical Polarization and Ellipsometry #Optical and Acousto-Optic Technologies #Optics (physics.optics) #Photorefractive and Nonlinear Optics
paper · doi:10.48550/arxiv.2008.10512
openalex publication_date 2020/08/24 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We investigate, theoretically and numerically, the dependence of a material's nonlinear-optical response on the linear relative electric permittivity ε and magnetic permeability μ. The conversion efficiency of low-order harmonic-generation processes, as well as the increase rate of Kerr-effect nonlinear phase shift and nonlinear losses from two-photon absorption (TPA), are seen to increase with decreasing ε and/or increasing μ. We also discuss the rationale and physical insights behind this nonlinear response, particularly its enhancement in ε-near-zero (ENZ) media. This behavior is consistent with the experimental observation of intriguingly high effective nonlinear refractive index in degenerate semiconductors such as indium tin oxide [Alam et al., Science 352 (795), 2016] (where the nonlinearity is attributed to a modification of the energy distribution of conduction-band electrons due to laser-induced electron heating) and aluminum zinc oxide [Caspani et al., Phys. Rev. Lett. 116 (233901), 2016] at frequencies with vanishing real part of the linear permittivity. Such strong nonlinear response can pave the way for a new paradigm in nonlinear optics with much higher conversion efficiencies and therefore better miniaturization capabilities and power requirements for next-generation integrated nanophotonics.