Mechanical equivalence of spin and orbital angular momentum of light: An optical spanner

N. B. Simpson, K. Dholakia, L. Allen, M. J. Padgett

Research output: Contribution to journalArticle

796 Citations (Scopus)

Abstract

We use a Laguerre-Gaussian laser mode within an optical tweezers arrangement to demonstrate the transfer of the orbital angular momentum of a laser mode to a trapped particle. The particle is optically confined in three dimensions and can be made to rotate; thus the apparatus is an optical spanner. We show that the spin angular momentum of ± (Latin small letter h with stroke sign) per photon associated with circularly polarized light can add to, or subtract from, the orbital angular momentum to give a total angular momentum. The observed cancellation of the spin and orbital angular momentum shows that, as predicted, a Laguerre-Gaussian mode with an azimuthal mode index l = 1 has a well-defined orbital angular momentum corresponding to (Latin small letter h with stroke sign) per photon.

Original languageEnglish
Pages (from-to)52-54
Number of pages3
JournalOptics Letters
Volume22
Issue number1
DOIs
Publication statusPublished - 1997 Jan 1

All Science Journal Classification (ASJC) codes

  • Atomic and Molecular Physics, and Optics

Fingerprint Dive into the research topics of 'Mechanical equivalence of spin and orbital angular momentum of light: An optical spanner'. Together they form a unique fingerprint.

  • Cite this