157 36 70 4 785 document 70 Daniel_Giovannini_dataset.zip application/x-zip 63233714f5578b5f1c43c70ae0b156c3 MD5 3873161 2015-04-02 09:09:48 https://researchdata.gla.ac.uk/157/1/Daniel_Giovannini_dataset.zip 157 1 1 application/x-zip Mixed Dataset including anaysis, raw data and documentation. en public cc_by_sa_4

Daniel_Giovannini_dataset.zip

full_archive archive 5 disk0/00/00/01/57 2015-04-02 09:28:25 2025-06-05 10:26:45 2015-04-02 11:37:56 data_collection show Giovannini Daniel Romero Jacquiline Potoček Václav Ferenczi Gergely Speirits Fiona 5708 Barnett Stephen 26813 0000-0003-0733-4524 Faccio Daniele 45729 0000-0001-8397-334X Padgett Miles 10309 0000-0001-6643-0618 glaresearchdata:2015-03-21-157 pub 30600000 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 wavevectors 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 of 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 the order of 1 m. Our work highlights that, even in free space, the invariance of the speed of light only applies to plane waves. 2015-03-21 published University of Glasgow 10.5525/gla.researchdata.157 Mixed University of Glasgow 54987 1 Challenges in Orbital Angular Momentum Miles Padgett Engineering and Physical Sciences Research Council (EPSRC) EP/I012451/1 P&A - PHYSICS & ASTRONOMY 62450 1 TWISTS - Twists & more: the complex shape of light Miles Padgett European Research Council (ERC) 340507 S&E P&A - PHYSICS & ASTRONOMY 54987 2 Challenges in Orbital Angular Momentum Miles Padgett Engineering and Physical Sciences Research Council (EPSRC) EP/I012451/1 P&A - PHYSICS & ASTRONOMY FALSE en http://dx.doi.org/10.1126/science.aaa3035 article 2034-11-30 D 2025-02-11 AA Original retention date approaching. Decision taken to extend 10 years from last access date and Review. 72 downloads and 1,336 hits. 10309 FALSE FALSE http://eprints.gla.ac.uk/id/eprint/102869