# Single-Step Shaping of the Orbital Angular Momentum Spectrum of Light

## TL;DR

This paper introduces a novel single-step method for arbitrarily modifying the orbital angular momentum spectrum of light, enabling complete control in a single step without prior spectrum knowledge, with potential applications in information processing.

## Contribution

The paper presents a new approach using binary ring apertures on spatial light modulators for single-step OAM spectrum modulation, filling a gap in existing optical control techniques.

## Key findings

- Achieved complete OAM spectrum control in a single step.
- Demonstrated the method's effectiveness with experimental implementation.
- Potential applications in classical and quantum information processing.

## Abstract

Control of orbital angular momentum (OAM) in optical fields has seen tremendous growth of late, with a myriad of tools existing for their creation and detection. What has been lacking is the ability to arbitrarily modify the OAM spectrum of a superposition in amplitude and phase, especially if a priori knowledge of the initial OAM spectrum is absent. Motivated by a quasi-mapping that exists between the position and OAM of Laguerre-Gaussian modes, we propose an approach for single-step modulation of a field's OAM spectrum. We outline the concept and implement it through the use of binary ring apertures encoded on spatial light modulators. We show that complete control of the OAM spectrum is achievable in a single step, fostering applications in classical and quantum information processing that utilise the OAM basis.