Dividing by zero — infinite velocities and unbounded nonlinear optics in low-index media

Orad Reshef
University of Ottawa, Ontario

Abstract

The refractive index is the single defining quantity for determining the behaviour of light propagation in a medium. Recent advances by the metamaterials community have resulted in fine control over this value in both composite and bulk materials, tuning the index to negative values and even down to zero [1]. These exotic materials exhibit extreme and counter-intuitive properties, including infinite phase velocities and seemingly diverging optical nonlinearities.

In my talk, I will first discuss the recent progress in developing monolithic zero-index metamaterials in the standard silicon-on-insulator platform [2], and how we used this material to produce and directly image light waves with infinite wavelengths at optical frequencies [3]. I will then present our recent experiments exploiting the giant ultrafast nonlinearities of another low-index material, indium tin oxide, and how this class of materials enters a non-perturbative regime of nonlinear optics [4]. Our work has important implications for the fundamental understanding of nonlinear optical phenomena and enables novel applications in ultra-thin active photonics devices.

Bio

Dr. Orad Reshef is working in nanophotonics, metamaterials and nonlinear optics. After completing a bachelor’s degree with First Class Honours in Physics at McGill University in Montreal, he joined Prof. Eric Mazur at Harvard University to pursue his doctoral studies. There, he worked on photonic titanium dioxide, integrated zero-index metamaterials, and their applications in nonlinear optics. Currently, Orad is a Banting postdoctoral fellow under Robert Boyd in the CERC group at the University of Ottawa, where he is working on nonlinear optics in epsilon-near-zero (ENZ) materials, high-Q metasurfaces based on surface lattice resonances, and nonlocal metamaterials. He is interested in scalable integrated photonic devices, and on engineering nonlinear interactions and devices that are not typically found in nature by structuring materials on the nanoscale. More information on Orad can be found online on his portfolio website: reshef.ca