Atomic optical spatial mode extractor for vector beams based on polarization-dependent absorption

Abstract

Vector beams with spiral phase and spatially varying polarization profiles have many applications from optical micromanipulation to materials processing. Here, we propose and demonstrate an atomic spatial mode extracting scheme for the vector beam based on polarization-dependent absorption in the atom vapor. By employing the linear polarization pump beam which induces polarization sensitive absorption in the atomic ensemble, a counter-propagated weak probe vector beam is extracted by spatial absorption, and extracted part still maintains the original polarization and the vortex phase. The topological charges of the extracted mode are verified by interfering with the Gaussian beam, and it can be found that the orbital angular momentum is conserved in the extracting process. Our work will have potential applications in non-destructive spatial mode identification, and is also useful for studying higher-dimensional quantum information based on atomic ensembles.

Spatial quantum coherent modulation with perfect hybrid vector vortex beam based on atomic medium

“…For instance, VVBs have been studied with high-dimensional information coding in quantum memory, [15] and a novel type of spatial mode selector has also been demonstrated in atom vapor. [16][17][18] The magic behind this kind of atom-light interaction modulation is the spatial atomic quantum coherence. [19,20] Principally, quantum coherence occurs in the interaction between light and atoms, which can be realized by two laser beams coupling with a three-level system.…”