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

763 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

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equivalence
angular momentum
orbitals
laser modes
strokes
trapped particles
photons
cancellation
polarized light

All Science Journal Classification (ASJC) codes

  • Atomic and Molecular Physics, and Optics

Cite this

Simpson, N. B. ; Dholakia, K. ; Allen, L. ; Padgett, M. J. / Mechanical equivalence of spin and orbital angular momentum of light : An optical spanner. In: Optics Letters. 1997 ; Vol. 22, No. 1. pp. 52-54.
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Mechanical equivalence of spin and orbital angular momentum of light : An optical spanner. / Simpson, N. B.; Dholakia, K.; Allen, L.; Padgett, M. J.

In: Optics Letters, Vol. 22, No. 1, 01.01.1997, p. 52-54.

Research output: Contribution to journalArticle

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