Decomposing spatial mode superpositions with a triangular optical cavity

TL;DR

This paper demonstrates that a triangular optical cavity can efficiently decompose and sort Hermite-Gaussian modes, with potential applications in quantum information and sensitive optical measurements.

Contribution

It introduces a novel use of a triangular cavity as a mode discriminator and proposes a cavity sequence for mode sorting without optical isolation.

Findings

Effective decomposition of paraxial fields into cavity modes.

High purity mode discrimination suitable for quantum applications.

Proposal of a cavity sequence for mode sorting without optical isolators.

Abstract

We demonstrate that a triangular cavity can operate as an efficient discriminator for Hermite-Gaussian optical modes. The process is applied to distinct fields produced by a Spatial Light Modulator, decomposing the generated paraxial field onto a basis of modes defined by the resonant modes of the optical cavity. We also present a proposal for the realization of a mode sorter based on a sequence of these cavities, without the need for optical isolation. We discuus its possible applications in sensitive measurements and distribution of information in optical systems. The high purity of the process should enable the use at the level of quantum information sharing.