title: Tunable dark modes in one-dimensional "diatomic" dielectric gratings.
abstract: Recently researchers have demonstrated ultra high quality factor (Q) resonances in one-dimensional (1D) dielectric gratings. Here we theoretically investigate a new class of subwavelength 1D gratings, namely "diatomic" gratings with two nonequivalent subcells in one period, and utilize their intrinsic dark modes to achieve robust ultra high Q resonances. Such "diatomic" gratings provide extra design flexibility, and enable high Q resonators using thinner geometry with smaller filling factors compared to conventional designs like the high contrast gratings (HCGs). More importantly, we show that these high Q resonances can be efficiently tuned in situ, making the design appealing in various applications including optical sensing, filtering and displays.
authors.forename: Bo
authors.initials: B
authors.lastname: Zeng
authors.forename: Arka
authors.initials: A
authors.lastname: Majumdar
authors.forename: Feng
authors.initials: F
authors.lastname: Wang