Fano interference between resonant and leaky waves in 1D silicon photonic crystal microcavities

摘要

Resonant integrated optical structures with spectra exhibiting asymmetric Fano line shapes [1] are of interest for a variety of devices, including integrated sensors, electro-optic modulators and all-optical switches. Here we observe such line shapes in the transmission spectra of waveguide-loaded 1D photonic crystal (PC) microresonators, resulting from interference between the resonant transmission of the bus WG's fundamental quasi-TE mode, and leaky nonresonant transmission of a second-order quasi-TE mode through the PC region. The continuum state transmitted through the PC microcavity itself uniquely allows for devices requiring no additional waveguides or reflecting elements [2]. Additionally, the devices are fabricated with 193-nm immersion photolithography in a CMOS memory process at Micron Technology [3], and though PC structures have previously been fabricated photolithographically [4], these are the first high-Q PC microcavity devices fabricated subject to the constraints and dielectric environment of a full electronics-capable CMOS process.