The photon: A virtual reality

Andrews, D. L. (2005) The photon: A virtual reality. In: Nature of Light: What is a Photon? Proceedings of the Society of Photo-Optical Instrumentation Engineers (Spie), 5866 . CRC Press, pp. 1-7. ISBN 0277-786X 0-8194-5871-6

[thumbnail of 169]
PDF (169) - Accepted Version
Download (96kB) | Preview


It has been observed that every photon is, in a sense, virtual - being emitted and then sooner or later absorbed. As the motif of a quantum radiation state, the photon shares these characteristics of any virtual state: that it is not directly observable; and that it can signify only one of a number of indeterminable intermediates, between matter states that are directly measurable. Nonetheless, other traits of real and virtual behavior are usually quite clearly differentiable. How 'real', then, is the photon? To address this and related questions it is helpful to look in detail at the quantum description of light emission and absorption. A straightforward analysis of the dynamic electric field, based on quantum electrodynamics, reveals not only the entanglement of energy transfer mechanisms usually regarded as 'radiative' and 'radiation less'; it also gives significant physical insights into several other electromagnetic topics. These include: the propagating and non-propagating character in electromagnetic fields; near-zone and wave-zone effects; transverse and longitudinal character; the effects of retardation, manifestations of quantum uncertainty and issues of photon spin. As a result it is possible to gain a clearer perspective on when, or whether, the terms 'real' and 'virtual' are helpful descriptors of the photon.

Item Type: Book Section
Additional Information: Conference on Nature of Light - What is a Photon AUG 01-02, 2005 San Diego, CA
Faculty \ School: Faculty of Science > School of Chemistry
UEA Research Groups: Faculty of Science > Research Groups > Physical and Analytical Chemistry (former - to 2017)
Faculty of Science > Research Groups > Chemistry of Light and Energy
Faculty of Science > Research Groups > Centre for Photonics and Quantum Science
Depositing User: Rachel Smith
Date Deposited: 19 Apr 2011 14:56
Last Modified: 19 Jul 2024 23:50
DOI: isbn:0277-786X 0-8194-5871-6


Downloads per month over past year

Actions (login required)

View Item View Item