Universal light-guiding geometry for on-chip resonators having extremely high Q-factor
Dae‐Gon Kim, Sangyoon Han, Joonhyuk Hwang, In Hwan, Dongin Jeong, Jihun Lim, Yong-Hoon Lee, Muhan Choi, Yong-Hee Lee, Duk‐Yong Choi, Hansuek Lee
Abstract
Abstract By providing an effective way to leverage nonlinear phenomena in integrated devices, high-Q optical resonators have led to recent advances in on-chip photonics. However, developing fabrication processes to shape any new material into a resonator with extremely smooth surfaces on a chip has been an exceptionally challenging task. Here, we describe a universal method to implement ultra-high-Q resonators with any new material having desirable properties that can be deposited by physical vapor deposition. Using this method light-guiding cores with surface roughness on the molecular-scale are created automatically on pre-patterned substrates. Its efficacy has been verified using As 2 S 3 , a chalcogenide glass that has high-nonlinearity. The Q-factor of the As 2 S 3 resonator so-developed approached the propagation loss record achieved in chalcogenide fibers which were limited by material losses. Owing to the boosted Q-factor, lasing by stimulated Brillouin scattering has been demonstrated with 100 times lower threshold power than the previous record.