The field distribution of Laguerre-Gaussian laser modes has a phase which depends on the azimuthal angle, ϕ, of the form ϕ, where ϕ = 0, ± 1, ± 2, = 3 etc. It has been shown by Allen et al. that this azimuthal phase dependence gives rise to a well defined orbital angular momentum which corresponds to ϕ per photon in the mode. As is well known, circularly polarised light also carries an angular momentum associated with the photon spin corresponding to ϕ per photon. Recent work by He et al.  has shown qualitatively that angular momentum can be transferred from a linearly polarised Laguerre-Gaussian mode to an optically trapped ceramic or metal oxide particle. However, their work does not prove that orbital angular momentum is well defined at ϕ per photon. We report progress in, what we believe to be, the first experimental confirmation that the orbital angular momentum of a linearly polarised Laguerre-Gaussian mode is indeed ϕ per photon.
© 1996 Optical Society of AmericaPDF Article
More Like This
K. Dholakia, N.B. Simpson, M. J. Padgett, and L. Allen
QPD6 Quantum Electronics and Laser Science Conference (QELS) 1996
ThL4 Frontiers in Optics (FiO) 2003
J. Courtial, K. Dholakia, L. Allen, and M.J. Padgett
QThB2 Quantum Electronics and Laser Science Conference (QELS) 1997