Suppression of Disorder-Induced Scattering in Optomechanical Systems
University of Illinois at Urbana-Champaign
Disorder-induced scattering – caused by surface roughness or defects inside medium – is inherent in optical and acoustic devices, limiting performance in communication systems. Minimizing disorder-induced scattering has thus been a significant challenge until now. It has been shown that backscattering from defects can be suppressed by breaking time-reversal symmetry in magneto-optic and topological insulator materials. Yet, common monolithic dielectric possesses neither of these properties.
In this talk, I will address a novel technique to break time-reversal symmetry in a high-Q optical whispering gallery mode resonator via parity-selective optomechanics mediated by Brillouin scattering. These optomechanical interactions are possible in all dielectric without exception and can be used to achieve time-reversal symmetry breaking. Through the Brillouin optomechanics, I will present the recent demonstration of robust phonon and photon transports in the presence of material disorder.
About the Speaker
Seunghwi Kim received a Ph.D in Mechanical Engineering from the University of Illinois at Urbana-Champaign under the guidance with Prof. Gaurav Bahl. He holds a B.S in Mechanical Engineering and Electrical Engineering from Handong University, South Korea. He elucidated ways of breaking time-reversal symmetry via optomechanics and acousto-optics, and demonstrated suppression of disorder-induced scattering in acoustic and optical domains.