Optical memory for arbitrary perfect Poincaré states in an atomic ensemble

Abstract

Inherent spin angular momentum (SAM) and orbital angular momentum (OAM), which manifest as polarization and spatial degrees of freedom (DOFs) of photons, hold a promise of large capability for applications in classical and quantum information processing. To enable these photonic spin and orbital dynamic properties strongly coupled with each other, Poincaré states have been proposed and offer advantages in data multiplexing, information encryption, precision metrology, and quantum memory. However, since the transverse size of Laguerre–Gaussian beams strongly depends on their topological charge numbers | l |, it is difficult to store asymmetric Poincaré states due to the significantly different light–matter interaction for distinct spatial modes. Here, we experimentally realize the storage of perfect Poincaré states with arbitrary OAM quanta using the perfect optical vortex, in which 121 arbitrarily selected perfect Poincaré states have been stored with high fidelity. The reported work has great prospects in optical communication and quantum networks for dramatically increased encoding flexibility of information.

Digital generation of super-Gaussian perfect vortex beams via wavefront shaping with globally adaptive feedback

“…In contrast, PVBs are featured with size-tunable and OAM-independent annulus patterns despite only being true at the Fourier plane. This ‘perfect’ OAM-carrying light provides a unique interface of light–matter interaction and thus has important applications in optical trapping and manipulation, quantum information processing [ 19 ] , etc. The complex field of an ideal PVB with the topological charge of l is defined in the following model [ 9 ] : where denote the polar coordinates, is the Dirac delta function and r 0 defines the radius of the PVB.…”

Shape-preserving storage of elegant Ince-Gaussian modes in warm atomic vapor

“…Multimode photonic quantum memory has been a research interest recently since it can effectively increase the information processing speed [4][5][6][7] . Photons encoded in the spatial degree, the spectral degree, and the temporal degree or their combinations have been successfully stored in media, such as a cold atomic ensemble [8][9][10][11] , a hot atomic vapor cell [12][13][14][15] , and a doped solid system [6,16,17] . Among them, the hot atomic vapor has the advantage of easy implementation, low cost, and being capable of integration.…”