The enigma of optical momentum in a medium

Barnett, S.M. and Loudon, R. (2010) The enigma of optical momentum in a medium. Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences, 368(1914), pp. 927-939. (doi: 10.1098/rsta.2009.0207)

Abstract

It is 100 years since Minkowski and Abraham first gave rival expressions for the momentum of light in a material medium. At the single-photon level, these correspond, respectively, either to multiplying or dividing the free-space value (Graphic) by the refractive index (n). The debate that this work started has continued till the present day, punctuated by the occasional publication of ‘decisive’ experimental demonstrations supporting one or other of these values. We review the compelling arguments made in support of the Minkowski and Abraham forms and are led to the conclusion that both momenta are correct. We explain why two distinct momenta are needed to describe light in a medium and why each appears as the natural, and experimentally observed, momentum in appropriate situations.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Barnett, Professor Stephen
• Authors: Barnett, S.M., and Loudon, R.
• College/School: College of Science and Engineering > School of Physics and Astronomy
• Journal Name: Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences
• Publisher: Royal Society
• ISSN: 1364-503X
• ISSN (Online): 1471-2962
• Copyright Holders: Copyright © 2010 The Authors
• First Published: First published in Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences 368(1914):927-939
• Publisher Policy: Reproduced under a Creative Commons License