Spatially structured photons that travel in free space slower than the speed of light

Giovannini, Daniel, Romero, Jacquiline, Potocek, Vaclav, Ferenczi, Gergely, Speirits, Fiona, Barnett, Stephen M., Faccio, Daniele and Padgett, Miles J. (2015) Spatially structured photons that travel in free space slower than the speed of light. Science, 347 6224: 857-860. doi:10.1126/science.aaa3035


Author Giovannini, Daniel
Romero, Jacquiline
Potocek, Vaclav
Ferenczi, Gergely
Speirits, Fiona
Barnett, Stephen M.
Faccio, Daniele
Padgett, Miles J.
Title Spatially structured photons that travel in free space slower than the speed of light
Journal name Science   Check publisher's open access policy
ISSN 1095-9203
0036-8075
Publication date 2015-02-01
Sub-type Article (original research)
DOI 10.1126/science.aaa3035
Open Access Status Not yet assessed
Volume 347
Issue 6224
Start page 857
End page 860
Total pages 4
Place of publication Washington, DC, United States
Publisher American Association for the Advancement of Science
Language eng
Formatted abstract
That the speed of light in free space is constant is a cornerstone of modern physics. However, light beams have finite transverse size, which leads to a modification of their wave vectors resulting in a change to their phase and group velocities. We study the group velocity of single photons by measuring a change in their arrival time that results from changing the beam’s transverse spatial structure. Using time-correlated photon pairs, we show a reduction in the group velocity of photons in both a Bessel beam and photons in a focused Gaussian beam. In both cases, the delay is several micrometers over a propagation distance of ~1 meter. Our work highlights that, even in free space, the invariance of the speed of light only applies to plane waves.
Q-Index Code C1
Q-Index Status Provisional Code
Institutional Status Non-UQ

Document type: Journal Article
Sub-type: Article (original research)
Collection: School of Mathematics and Physics
 
Versions
Version Filter Type
Citation counts: TR Web of Science Citation Count  Cited 22 times in Thomson Reuters Web of Science Article | Citations
Scopus Citation Count Cited 20 times in Scopus Article | Citations
Google Scholar Search Google Scholar
Created: Sat, 01 Apr 2017, 01:00:35 EST by Web Cron on behalf of Learning and Research Services (UQ Library)