New chip-scale laser isolator opens new research avenues in photonics

https://phys.org/news/2022-12-chip-scale-laser-isolator-avenues-photonics.html

"passive... requires no external inputs, complicated electronics, or magnetics... made from common semiconductor-based material... shaped like ring... silicon nitride based on silicon... laser enters ring and photons spin around ring... back-reflected beam sent back into ring in opposite direction... laser power input circulates many times... increasing power alters weaker beam, while stronger continues unaffected... reflected light effectively canceled... primary laser exits ring and isolated in desired direction"

Related: Driving the era of silicon photonics with integrated lasers

https://www.laserfocusworld.com/optics/article/14288068/driving-the-era-of-silicon-photonics-with-integrated-lasers