Lecturer: Dr. Yaron Bromberg
Affiliation: Yale University
Abstract:
Multiple scattering of light leads to universal
coherent phenomena that are surprisingly robust
to ensemble averaging. A prominent example is
coherent backscattering, where time-reversed
paths inside a complex disordered sample
interfere constructively and enhance the
backscattered light. The constructive interference
is insensitive to averaging over disorder
realizations, by virtue of the optical reciprocity
principle. An open question is whether it is
possible to take advantage of such coherent
phenomena to control the light transport in a
robust manner, which does not depend on the
exact configuration of the disordered sample.
In my talk I will present our recent work towards
this end. We demonstrated a control over the
interference of time-reversed paths inside a
multimode fiber with strong mode mixing. By
exploiting a non-reciprocal magneto-optical effect,
we were able to observe a continuous transition
from a peak to a dip in the backscattered light,
where the transition was insensitive to the
configuration of the fiber.
I will also show how we can utilize the mode
mixing in multimode fibers and the robust
interference of time-reversed paths, for secure
optical communication.