Optical measurement of torque exerted on an elongated object by a noncircular laser beam

2004/03/31 by Simon J. Parkin, Timo A. Nieminen, N. R. Heckenberg +3 · 1 citation
Engineering · Physics and Astronomy · #Digital Holography and Microscopy #Near-Field Optical Microscopy #Orbital Angular Momentum in Optics #physics.optics

paper · pdf · doi:10.1103/physreva.70.023816

published as Physical Review A, 70(2), 023816 (2004) · 6 pages, 7 figures, v2: minor typographical corrections

arxiv created 2004/08/26 · openalex publication_date 2004/08/26 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28

Abstract

We have developed a scheme to measure the optical torque exerted by a laser beam on a phase object by measuring the orbital angular momentum of the transmitted beam. The experiment is a macroscopic simulation of a situation in optical tweezers, as orbital angular momentum has been widely used to apply torque to microscopic objects. A hologram designed to generate LG₀₂ modes and a CCD camera are used to detect the orbital component of the beam. Experimental results agree with theoretical numerical calculations, and the strength of the orbital component suggest its usefulness in optical tweezers for micromanipulation.

Citations

• Optical alignment and spinning of laser-trapped microscopic particles
• Orbital angular momentum of light and the transformation of Laguerre-Gaussian laser modes

Cited by

• Symmetry and the generation and measurement of optical torque

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