Special lens with a conical surface
Diagram of Axicon and resulting Bessel Beam
An axicon is a specialized type of lens that has a conical surface. An axicon transforms a laser beam into a ring shaped distribution.[ 1] They can be convex or concave and be made of any optical material. The combination with other axicons or lenses allows a wide variety of beam patterns to be generated. It can be used to turn a Gaussian beam into a non-diffractive Bessel -like beam.[ 2] Axicons were first proposed in 1954 by John McLeod.[ 3]
Axicons are used in atomic traps and for generating plasma in wakefield accelerators .[ 4] They are used in eye surgery in cases where a ring-shaped spot is useful.
The Axicon is usually characterized by the ratio of the diameter of the ring to the distance from the lens tip to image plane d/l.
^ Mallik, Proteep (2005). "The Axicon" (PDF) . University of Arizona College of Optical Sciences. Retrieved 12 December 2014 . [unreliable source? ]
^ Garcés-Chávez, V.; McGloin, D.; Melville, H.; Sibbett, W.; Dholakia, K. (Sep 12, 2002). "Simultaneous micromanipulation in multiple planes using a self-reconstructing light beam" (PDF) . Nature . 419 (6903): 145–7. Bibcode :2002Natur.419..145G . doi :10.1038/nature01007 . PMID 12226659 . S2CID 4426776 . Archived from the original (PDF) on September 19, 2006.
^ McLeod, John H. (1954). "The axicon: A new type of optical element". J. Opt. Soc. Am . 44 (8): 592. Bibcode :1954JOSA...44..592M . doi :10.1364/JOSA.44.000592 .
^ Green, S. Z.; Adli, E.; Clarke, C. I.; Corde, S.; Edstrom, S. A.; Fisher, A. S.; Frederico, J.; Frisch, J. C.; Gessner, S.; Gilevich, S.; Hering, P. (2014-07-22). "Laser ionized preformed plasma at FACET" . Plasma Physics and Controlled Fusion . 56 (8): 084011. Bibcode :2014PPCF...56h4011G . doi :10.1088/0741-3335/56/8/084011 . ISSN 0741-3335 .