Scalable orbital-angular-momentum sorting without destroying photon states

TL;DR

This paper introduces a scalable, nondestructive OAM photon sorter using symmetric multiport beam splitters and Dove prisms, capable of efficiently categorizing high-dimensional OAM states while preserving photon properties.

Contribution

The authors propose a novel, scalable OAM sorter that reduces complexity and can sort high-dimensional OAM states without destroying photon states, advancing quantum information processing.

Findings

Reduces the number of beam splitters needed for high-dimensional OAM sorting

Preserves both OAM and spin angular momentum during sorting

Applicable to high-dimensional quantum information and traditional optics

Abstract

Single photons with orbital angular momentum (OAM) have attracted substantial attention from researchers. A single photon can carry infinite OAM values theoretically. Thus, OAM photon states have been widely used in quantum information and fundamental quantum mechanics. Although there have been many methods for sorting quantum states with different OAM values, the nondestructive and efficient sorter of high-dimensional OAM remains a fundamental challenge. Here, we propose a scalable OAM sorter which can categorize different OAM states simultaneously, meanwhile, preserving both OAM and spin angular momentum. Fundamental elements of the sorter are composed of symmetric multiport beam splitters (BSs) and Dove prisms with cascading structure, which in principle can be flexibly and effectively combined to sort arbitrarily high-dimensional OAM photons. The scalable structures proposed here greatly reduce the number of BSs required for sorting high-dimensional OAMstates. In view of the nondestructive and extensible features, the sorters can be used as fundamental devices not only for high-dimensional quantum information processing, but also for traditional optics.