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PhD Proposal: Hari Lamsal

Thursday, July 12, 2018
2:00 PM - 3:30 PM
Physics : 401
ADVISOR: Dr. Todd Pittman

TITLE: Ultralow-power nonlinear optics using optical nanofibers in metastable xenon

ABSTRACT:Nonlinear optics (NLO) is a very broad field with applications ranging from frequency conversion and all-optical switching to quantum computing. For many of these applications, the use of low power lasers is desirable. Consequently, there is currently a push for the realization of new physical platforms enabling ultralow-power NLO. Here I propose research on a promising ultralow-power NLO platform consisting of an optical nanofiber (ONF) suspended in a gas of metastable xenon atoms (Xe*). The origin of the strong nonlinearity in this platform is due to the tight confinement of the ONF guided evanescent mode (~1 μm) over a long distance (~1 cm), and a resonant interaction of the mode with the surrounding atoms. In contrast to typical NLO platforms using high power (W-kW, cw) lasers, we anticipate the observation of nonlinear effects using nW-pW power levels.

Previous work in this area using Rubidium (a reactive alkali metal) as the atomic medium has suffered from severe performance limitations due to Rb accumulation on the ONF surface. This suggests the use of Xe* (an inert nobel gas) as a superior choice for practical applications. Here we propose to investigate the basic physics and demonstrate the utility of the “ONF in Xe*” platform by performing a series of ultralow-power NLO experiments using this promising system. The experimental work combines techniques from traditional NLO, atomic spectroscopy, ultra-high vacuum science, and quantum optics.