UC Berkeley

Over the past few years, tremendous effort has gone into the development of various optical building blocks for the silicon photonics platform. Part of the allure is that photonics circuits on silicon can be very small and leverage over 5 decades of scaling and existing microelectronics infrastructure. As such, photonic integrated circuits (PICs) on silicon are poised to address the ever-growing high-bandwidth needs of the servers and data centers of tomorrow, where the high-volume processing of a silicon platform and the low cost of traditional optical communications could redefine the constraints of high-performance interconnects.

High contrast metastructures (HCMs) are an emerging solution for flat integrated photonic devices. These ultra-thin semiconductor ribbons can exhibit extraordinary properties that are atypical to traditional optical gratings, such as very broadband reflection at normal and shallow angles, high-Q resonances, and a readily engineered phase response. These properties have allowed for the design of a variety of novel optoelectronic devices such as vertical-cavity surface-emitting lasers (VCSELs), phase-arrays, lenses, and sensors.

In this work, we explore three different types of novel HCMs on silicon. The first is a hollow-core waveguide that can channel light at wavelengths where traditional solid waveguides encounter difficulties; next is a silicon-based HCG VCSEL with the potential of being an efficient light source for silicon PICs; and lastly, an integrated wavelength meter, which can circumvent bulky off-the shelf instruments to provide wavelength characterization of guided light on a chip.