Efficient full state tomography of the orbital angular momentum states of light using Helicity sorter

TL;DR

This paper introduces a scalable, efficient method for full quantum state tomography of light's orbital angular momentum states using a novel helicity sorter, advancing quantum communication and computation capabilities.

Contribution

The paper presents the first scalable, efficient quantum state tomography method for OAM states using a helicity sorter, with two implementation setups.

Findings

Two optical setups for helicity sorting of OAM modes

Method scales efficiently with the number of modes

Enables full quantum state reconstruction of OAM states

Abstract

Orbital angular momentum (OAM) of light is a promising degree of freedom for quantum communication and quantum computation. However, efficient methods to transform and measure OAM modes are still not available readily. Here, we propose a method for full quantum state tomography for arbitrary OAM states of light. The key component in our scheme is the helicity sorter, a device that can sort OAM modes of a light beam based on their Helicity. We present two setups to implement the Helicity sorted, one requires $\mathcal{O}(N)$ number of optical elements for $2^N$ OAM modes, and the other uses spatial light modulators and is independent of the number of OAM modes. Ours is the first method to provide the efficient and scalable full quantum state tomography of the OAM modes and can be extremely important for quantum communication and quantum computation.