Profiling the Spatial Quantum Fluctuations

Spatial information of quantum light states is needed for various quantum optics applications such as communication and precision measurements. Squeezed states are of particular interest as noise can be reduced below the shot noise limit. We are developing a protocol for measuring the spatial profiles of such squeezed states. Reconstruction of single spatial squeezed modes is demonstrated and we are expanding the formalism to multimode cases. Our method is based on single pixel imaging techniques adapted to the quantum domain and combining it with homodyne detection. Full wavefront information, phase and amplitude, of the quantum state is extracted via measurement of interferometric contrast of the quantum quadrature variance. To generate a squeezed state, we use polarization self-rotation (PSR) in Rubidium atoms which yields squeezing at 795nm. But our method is agnostic to these specifics and can work with any wavelength that is compatible with the detector used. As a proof of concept, we present quantum squeezed state spatial mode modifications as a function of atomic density.