SEMINAR: Physics Seminar

Abstract: The talk will cover an intriguing yet powerful way of accelerating and trapping molecular hydrogen in a self-organized extremely deep potential well. In this new Lamb-Dicke regime of stimulated-Raman-scattering, hydrogen molecules inside a photonic bandgap hollow core fibre are deeply-trapped in self-nanostructured optical lattice to emit watt-level CW Stokes-radiation with sub-Doppler resolved spectral sidebands and with a sub-recoil linewidth as low as ~3 kHz, which is ~6 orders-of-magnitude narrower than what conventional stimulated Raman scattering predicts. The Stokes sub-Doppler spectrum shows a rich structure that includes Mollow triplet, molecular motional-sidebands and four-wave-mixing. In addition to this rich spectral structure, we observe a macroscopic dynamics whereby molecule acceleration can be observed with the naked eye via an IR viewer. This new route of trapping molecules could open new paths in several fields. To mention a few, we count trapping and cooling molecules, with the potential of achieving the same level of accomplishments as those with atoms, or manufacturing of gas nanostructures such as micro-mirrors and micro-cavities as we do with solid-state materials.

Biography Fetah Benabid is a CNRS director of research and honorary professor at the universities of Bath (UK) and Western Australia (Australia). He is the group founder and leader of Gas-Phase Photonic and Microwave Materials (GPPMM) at the CNRS UMR Xlim, Limoges, France. Fetah Benabid has pioneered the development of hollow-core photonic crystal fibres (HC-PCF) and their incorporation into scientific and technological applications. He is the inventor of Kagome HC-PCF and an all-fibre gas cells, coined photonic microcell (PMC). He is the inceptor of new optical guidance mechanism called inhibited coupling optical guidance that led to low loss optical fiber with negative curvature core-contour, and the “photonic tight-binding model” to explain the formation of photonic bandgap in photonic crystal fibres. Fetah Benabid research interests covers guided photonics, gas-phase based nonlinear and coherent optics. Fetah Benabid is also the founder of the start-up GLOphotonics market leader in hollow-core fibers for industrial applications.