Unidirectional reﬂection from an integrated “taiji” microresonatorPhotonics Research
- Allegra Calabrese, Fernando Ramiro-Manzano, Hannah Price, Stefano Biasi, Martino Bernard, Mher Ghulinyan, Iacopo Carusotto, and Lorenzo Pavesi
- received 03/18/2020; accepted 05/26/2020; posted 05/29/2020; Doc. ID 393070
- Abstract: We study light transmission and reflection from an integrated microresonator device, formed by a circular microresonator coupled to a bus waveguide, with an embedded S-shaped additional crossover waveguide element that selectively couples counter-propagating modes in a propagation-direction-dependent way. The overall shape of the device resembles a ``taiji' symbol, hence its name. While Lorentz reciprocity is preserved in transmission, the peculiar geometry allows us to exploit the non-Hermitian nature of the system to obtain high-contrast unidirectional reflection with negligible reflection for light incident in one direction and a significant reflection in the opposite direction.