AMO/QO SEMINAR SERIES
"Coherent optical fluctuations in a white cavity : new spectroscopies for soft matter and beyond"
IBS Center for Soft and Living Matter, Ulsan National Institute for Science and Technology, Ulsan, South Korea
Light scattering and interferences are essential for understanding a wide range of phenomena in nature. In the
context of soft matter, the dynamical properties of speckles induced by coherent multiple scattering reveal
important information on the properties of disordered materials. I will first show how the activity of a motor
protein, namely myosin, can generate multiple scattering, and speckle fluctuations that reveal the conformational
dynamics of that mechano-enzyme. Second, I will introduce a new kind of optical field obtained by injecting a
single frequency light into a Lambertian cavity with highly diffuse reflecting walls. We obtain the coherent
superposition of a very large number of waves that follow a probability distribution, with spherical symmetry and
translation invariance. While the cavity acts as a random interferometer, it produces a 3D speckle field with
strongly amplified fluctuations. With a pico-meter sensitivity, a 10-decades frequency range and a 4-decades signal
dynamics, we can detect fluctuations of the geometry of the cavity, or the sample it contains. Our concept of
Lambertian coherent optical cavity forms the basis for the development of new fluctuation spectroscopies to
explore soft matter physics and beyond.
Tuesday,April 9, 2019
IQSE Seminar Room, 12:00 Noon
Institute for Quantum Science and Engineering
Texas A&M University
Sandwich lunch to be served at 11:30 a.m.
Host: Dr. Marlan Scully
THE INSTITUTE FOR QUANTUM
SCIENCE AND ENGINEERING