Natural Crystal Structure for Generating Raman‐Like Orbital Angular Momentum States

TL;DR

This paper introduces a new method to generate controllable orbital angular momentum (OAM) light states using crystal anisotropy and thermal control.

Contribution

A novel strategy for symmetry breaking in OAM states using crystal gain anisotropy and thermal-driven tuning is introduced.

Findings

Thermal-driven tuning enables arbitrary OAM states from −2ћ to ћ.

Natural crystal anisotropy helps select the handedness of spiral phase fronts.

The method provides high integrability and controllability for structured light.

Abstract

Creation of structured light at‐source with determinate orbital angular momentum (OAM) states is a fascinating branch of modern optics, owing to their integrability, wavelength insensitivity, and high mode purity. However, mode degeneracy in spatially column‐symmetric cylindrical coordinate systems leads to a total zero OAM states which seriously limits their development and applications. Here, a strategy is proposed for symmetry breaking of the degenerate OAM states relying on the natural anisotropy of crystal gain, to select the handedness of the spatial spiral phase front and further tunable Raman‐like OAM states by thermal‐driven, experimentally realized arbitrary OAM states from −2ћ to ћ. The concept presented herein clarifies the contribution of intrinsic crystal property to the OAM states and opens a new route for an at‐source solution of structure light with high integrability and controllable OAM states.

This work proposes a strategy for symmetry breaking of the degenerate OAM states relying on the natural anisotropy of crystal gain, to select the handedness of the spatial spiral phase front and further tunable Raman‐like OAM states by thermal‐driven, which clarifies the contribution of intrinsic crystal property to the OAM states and opens a new route for an at‐source solution of structure light with high integrability and controllable OAM states.

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