Quantum Optics Seminar by Quentin Glorieux

Coupling nanocrystals quantum dots to tapered optical fibers and  using hot atomic vapor to generate quantum fluids of light.

I will present two experiments performed recently in the Quantum Optics group at LKB

First, I will as the question if a linear dipole emit circularly polarized light ?
By coupling of single nano-scaled light sources to a tapered optical nanofiber, we show how the polarization of the emitted light can be strongly modified by the vicinity of the fiber. By comparing polarization measurements to electron microscope images we found a configuration for which a linear dipole starts to radiate circularly polarized light.

In a second part, I will look present, recent experiments to study quantum fluids of light. As an alternative approach to the confined light in cavities, we use a monochromatic light field propagating in a non-linear χ(3) medium (a near-resonant rubidium vapor) showing an intensity dependent refractive index.
Under the paraxial approximation, the transverse amplitude of the field can be described using a striking analogy with the formalism of the Gross-Pitaevskii equation (GPE) for the macroscopic wave-function of a Bose-Einstein condensate.
This system therefore allow to study the time evolution of a 2D Bose gas and potentially realized quantum simulation with light.