Measurement of the Orbital Angular Momentum Spectrum of Partially Coherent Fields using Double Angular Slit Interference

TL;DR

This paper presents an interferometric technique using double angular slits to measure the orbital angular momentum spectrum of partially coherent fields, enabling characterization of high-dimensional quantum states.

Contribution

The authors introduce a novel interferometric method that uses angular slit interference and Fourier analysis to determine the OAM spectrum of partially coherent fields.

Findings

Successfully measured OAM spectrum of partially coherent fields.

Demonstrated the correlation between interference visibility and angular correlation function.

Potential application in quantum information protocols with high-dimensional states.

Abstract

We implement an interferometric method using two angular slits to measure the orbital angular momentum (OAM) mode spectrum of a partially coherent field. As the angular separation of the slits changes, an interference pattern for a particular OAM mode is obtained. The visibility of this interference pattern as a function of angular separation is equivalent to the angular correlation function of the field. By Fourier transforming the angular correlation function obtained from the double angular slit interference, we are able to calculate the OAM spectrum of the partially coherent field. This method has potential application for characterizing the OAM spectrum in high-dimensional quantum information protocols.