Single-shot Precise Ranging using Twisted Light

TL;DR

This paper presents a novel single-shot optical ranging method using twisted light and OAM modes, achieving micrometer accuracy for scattering surfaces by analyzing the rotation of petal-like patterns.

Contribution

The authors introduce a new single-shot optical ranging scheme leveraging OAM mode superpositions and pattern rotation analysis, enhancing accuracy and noise robustness over existing methods.

Findings

Quadratic enhancement in ranging accuracy with beam focusing.

Ranging uncertainty of a few micrometers under noise conditions.

Single-shot measurement achieves high precision without continuous detection.

Abstract

Over the past decade, optical orbital angular momentum (OAM) modes were shown to offer advantages in optical information acquisition. Here, we introduce a new scheme for optical ranging in which depth is estimated through the angular rotation of petal-like patterns produced by superposition of OAM modes. Uncertainty of depth estimation in our strategy depends on how fast the petal-like pattern rotates and how precisely the rotation angle can be estimated. The impact of these two factors on ranging accuracy are analyzed in presence of noise. We show that focusing the probe beam provides a quadratic enhancement on ranging accuracy because rotation speed of the beam is inversely proportional to the square of beam radius. Uncertainty of depth estimation is also proportional to uncertainty of rotation estimation, which can be optimized by picking proper OAM superposition. Finally, we unveil the possibility of optical ranging for scattering surface with uncertainties of few micrometers under noise. Unlike existing methods which rely on continuous detection for a period of time to achieve such ranging accuracy, our scheme needs only single-shot measurement.