Continuously Shaping Orbital Angular Momentum with an Analog Optical Vortex Transmitter

TL;DR

This paper introduces an analog optical vortex transmitter capable of continuously varying the orbital angular momentum of light, enabling advanced manipulation and quantum applications with a novel diffractive design.

Contribution

A new analog vortex transmitter design that continuously varies OAM using a bilaterally symmetric grating and aperture, expanding the capabilities of optical vortex generation.

Findings

Enables continuous variation of OAM in the entire rational range.

Preserves a spiniform phase with equally spaced singularities.

Potential for extension to other frequencies and applications.

Abstract

Dynamic generation of obitial angular momentum (OAM) of light has enabled complex manipulation of micro-particles, high-dimension quantum entanglement and optical communication. We report an analog vortex transmitter made of one bilaterally symmetric grating and an aperture, emitting optical vortices with the average OAM value continuously variant in the entire rational range. Benefiting from linearly-varying transverse dislocation along its axis of symmetry, this diffractive transmitter possesses extra degree of freedom in engineering broadband optical vortices meanwhile preserving a novel spiniform phase with equally spaced singularities. It unlimitedly increases the average OAM of light by embracing more singularities, which is significantly different from that for Laguerre-Gaussian (LG) and Bessel vortex beams. Realizing analog generation of OAM in a single device, this technique can be potentially extended to other frequencies and applied to a wide spectrum of developments on quantum physics, aperiodic photonics and optical manipulation.