Understanding and controlling phonons with light: From noise to quantum information
Will Renninger, UR Institute of Optics
Cavity optomechanics is a recent field that explores the radiation pressure mediated interaction between vibrations of nanostructured surfaces and light. This interaction has applications ranging from precision metrology to quantum information science. On the other hand, optical interactions with traveling acoustic waves known as Brillouin scattering has a long and distinct history with several exciting applications just beginning to emerge. This talk reviews these new directions for Brillouin scattering including a simple but advantageous system with the same ambitious goals as cavity optomechanics.
Brillouin scattering is considered the strongest optical nonlinearity and has been harnessed for light generation, slow light, materials characterization, and for beam cleaning. It is also considered an undesired source of noise for single-photon interactions and for applications like fiber communications. Here we show how Brillouin interactions can occur even when other optical nonlinearities are absent, in hollow-core fibers. We demonstrate that light can scatter from high frequency acoustic waves in dilute gases like air. In addition, we demonstrate a new but analogous nonlinear optical process in which light can scatter from traveling entropy waves, in addition to acoustic waves, in superfluid helium. Finally, by cryogenically enhancing the phonon lifetime in bulk crystals to coherence lengths longer than a meter, we show how Brillouin scattering is radically altered and optomechanical interactions can be enhanced by four orders of magnitude in a new platform for materials spectroscopy, precision metrology, and quantum information processing.
William Renninger received his B. S. and Ph. D. degrees in Applied Physics from Cornell University. After his Ph.D. he was a Postdoctoral Research Associate in the Department of Applied Physics at Yale University. He joined the Institute of Optics at the University of Rochester as an Assistant Professor in 2017. His research interest is in experimental light-matter interactions with a focus on ultrafast nonlinear optics and the coherent interaction between photons and phonons. He has co-authored >30 papers, one book chapter, >40 conference proceedings, holds three patents, and is a recent recipient of the University of Rochester Research Award.