Interlaced spin grating for optical wave filtering

TL;DR

Interlaced Spin Grating is a novel scheme for creating high-contrast, broadband spectro-spatial absorption gratings in inhomogeneously broadened media, enhancing optical filtering capabilities especially in Tm-doped crystals.

Contribution

This paper introduces the Interlaced Spin Grating scheme, demonstrating its effectiveness in producing large contrast gratings with unlimited bandwidth in inhomogeneous media.

Findings

Diffraction efficiency up to 18.3% in small angle configuration.

Diffraction efficiency up to 11.6% in large angle configuration.

Outperforms conventional gratings in Tm:YAG.

Abstract

Interlaced Spin Grating is a scheme for the preparation of spectro-spatial periodic absorption gratings in a inhomogeneously broadened absorption profile. It relies on the optical pumping of atoms in a nearby long-lived ground state sublevel. The scheme takes advantage of the sublevel proximity to build large contrast gratings with unlimited bandwidth and preserved average optical depth. It is particularly suited to Tm-doped crystals in the context of classical and quantum signal processing. In this paper, we study the optical pumping dynamics at play in an Interlaced Spin Grating and describe the corresponding absorption profile shape in an optically thick atomic ensemble. We show that, in Tm:YAG, the diffraction efficiency of such a grating can reach 18.3% in the small angle, and 11.6% in the large angle configuration when the excitation is made of simple pulse pairs, considerably outperforming conventional gratings.