-------- Original Message --------
Subject: Talk TODAY Vivek Venkataraman
Date: Fri, 15 Jun 2012 09:42:47 -0400
From: Marko Loncar <loncar(a)seas.harvard.edu>
To: loncargroup Group <loncargroup(a)seas.harvard.edu>du>,
<diamond(a)seas.harvard.edu>du>, Orad Reshef <orad(a)seas.harvard.edu>du>, Joan
Hamilton <hamilton(a)physics.harvard.edu>
When: TODAY (Friday, June 15, 2012,) at 2:00
Where: MDG135 (Maxwell-Dworkin)
*Title*– Few-photon nonlinear optics in photonic bandgap fibers
*Speaker*- Vivek Venkataraman
*Affiliation*- School of Applied and Engineering Physics, Cornell
University, Ithaca, NY, USA
*Abstract*-The ability to control light with light (all-optical
control) at ultralow powers has been a major avenue of research in
photonics, and it is critical to demonstrate such effects near the
single-photon level for quantum information applications. Alkali-metal
vapors such as rubidium (Rb) have been used extensively for
light-matter interactions due to the large cross section per atom and
well-defined energy level structure. Optical waveguides such as
photonic band-gap fibers (PBGFs) with a hollow core allow various
gases to be injected into the core and interact with single-mode
optical fields.We have demonstrated the ability to load hollow-core
optical fibers with rubidium vapor, and this system exhibits
exceptionally strong nonlinearities due to the tight light
confinement, high vapor density and long interaction length. We
observe efficient nonlinear optical interactions viz. four-wave mixing
and two-photon absorption at ultralow powers, orders of magnitude
lower than those in bulk vapor cells. We demonstrate all-optical
intensity and phase modulation with <20 photons, i.e. a few attojoules
of energy, in our Rb-PBGF system at fast timescales of <5 ns, thus
showing its potential for exploring nonlinear effects at ultralow
powers forquantum information applications.