High Contrast Metastructures for Integrated Optics
Constance Chang-Hasnain, James Ferrara, Li Zhu, Linda Li and Tianbo Sun
National Science Foundation, Defense Advanced Research Projects Agency and Army Research Office
A new class of planar optics using near-wavelength structures with a large refractive index contrast has emerged. This seemingly simple structure lends itself to extraordinary properties, which can be designed top-down based for integrated optics on a silicon or III-V compound substrate. In particular, near-wavelength gratings with large index contrast with its surrounding materials are referred as high-contrast gratings (HCG). The extraordinary features include an ultra broadband, high reflectivity reflector or low reflectivity transparent window, for light incident from arbitrary directions. Another feature is a high quality-factor resonance (Q>1E7) with surface-normal emission. We are investigating the rich physics, and a wide range of designs and device applications, including wavelength-tunable lasers, sensors, lenses, and hollow-core waveguides.