Omnidirectional field enhancements drive giant nonlinearities in epsilon-near-zero waveguides

Abstract

Bulk materials possessing a relative electric permittivity $\epsilon$ close to zero exhibit giant Kerr nonlinearities. However, harnessing this response in guided-wave geometries is not straightforward, due to the extreme and counter-intuitive properties of epsilon-near-zero materials. Here we investigate, through rigorous calculations of the Kerr nonlinear coefficient, how the remarkable nonlinear properties of such materials can be exploited in several different types of structures, including bulk films, plasmonic nanowires, and metal nanoapertures. We find the largest Kerr nonlinear response when both the modal area and the group velocity are simultaneously minimized, corresponding to omnidirectional field enhancement. The physical insights developed will be key for understanding and engineering nonlinear nanophotonic systems with extreme nonlinearities and point to new design paradigms.

References in corpus (9)

• Realization of an all-dielectric zero-index optical metamaterial
• Enhanced nonlinear refractive index in epsilon-near-zero materials
• Beyond the perturbative description of the nonlinear optical response of low-index materials
• Modular Hybrid Plasmonic Integrated Circuit -- Rotation, Nanofocusing and Nonlinear Enhancement
• Exceptional points and spectral singularities in active epsilon-near-zero plasmonic waveguides
• Optically induced metal-to-dielectric transition in Epsilon-Near-Zero metamaterials
• Two-peaked and flat-top perfect bright solitons in epsilon-near-zero nonlinear metamaterials: novel Kerr self-trapping mechanisms
• Epsilon-near-zero plasmonic waveguides to enhance nonlinear coherent light-matter interactions
• Spatial nonlinearity in anisotropic metamaterial plasmonic slot waveguides

Cited by in corpus (1)

• Ultrahigh free-electron Kerr nonlinearity in all-semiconductor waveguides for all-optical nonlinear modulation of mid-infrared light