The dark spots of Arago

  • P. Fischer (Creator)
  • Susan E. Skelton (Creator)
  • Christopher G. Leburn (Creator)
  • Casey T. Streuber (Creator)
  • Ewan M Wright (Creator)
  • Kishan Dholakia (Creator)



We explore the diffraction and propagation of Laguerre-Gaussian beams of varying azimuthal index past a circular obstacle both experimentally and numerically. When the beam and obstacle centers are aligned the famous spot of Arago, which arises for zero azimuthal index, is replaced for non-zero azimuthal indices by a dark spot of Arago, a simple consequence of the conserved phase singularity at the beam center. We explore how the dark spot of Arago behaves as the beam and obstacle centers are progressively misaligned, and find that the central dark spot may break into several dark spots of Arago for higher incident azimuthal index beams.
Date made available2007
  • The dark spots of Arago

    Fischer, P., Skelton, S. E., Leburn, C. G., Streuber, C. T., Wright, E. M. & Dholakia, K., Sep 17 2007, In: Optics Express. 15, 19, p. 11860-11873 14 p.

    Research output: Contribution to journalArticlepeer-review

    12 Scopus citations

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