Quantum Optics Seminar by Georg Enzian
Brillouin cavity optomechanics with whispering gallery microresonators
Cavity quantum optomechanics uses fields of light to generate and study quantum states of motion of macroscopic mechanical resonators and is one of the newest and most rapidly growing areas of quantum optics. Excitingly, the field pursues several different experimental directions including Fabry-Perot cavities with movable mirrors, levitated optomechanical systems, and other nano-optical implementations, each having their own advantages and disadvantages. In this talk, a new direction—Brillouin optomechanics—will be discussed, which unites several favourable properties including very high mechanical frequencies (> 10 GHz), very low optical loss and absorption, and back-scatter operation to allow the signal to be easily separated from the pump. Using a silica micro-resonator, we have experimentally observed Brillouin optomechanical strong coupling between the optical cavity field and these high-frequency mechanical vibrations [Optica 6, 7 (2019)]. Additionally, I will discuss a recent experiment performing single phonon addition and subtraction to a mechanical thermal state of the acoustic whispering gallery wave [in preparation]. This research opens a rich avenue for further studies that test the very foundations of quantum mechanics and the development of powerful new quantum technologies.