2005 (English)In: Proceedings of SPIE / [ed] Laurent Mazuray, Rolf Wartmann, SPIE - International Society for Optical Engineering, 2005Conference paper (Other academic)
The axicon is an optical element which creates a narrow focal line along the optical axis, unlike the single focal point produced by a lens. The long and precisely defined axicon focal line is used e.g. in alignment, or to extend the depth of focus of existing methods such as optical coherence tomography or light sectioning. Axicons are generally manufactured as refractive cones or diffractive circular gratings. They are also made as lens systems or doublet lenses, which are easier to produce. We present a design in the form of a reflective-refractive single-element device with annular aperture. This very compact system has only two surfaces, which can be spherical or aspheric depending on the quality required of the focal line. Both surfaces have reflective coatings at specific zones, providing an annular beam suitable for generating extended focal lines. One draw-back of a normal axicon is its sensitivity to the angle of illumination. Even for relatively small angles, astigmatism will broaden the focus and give it an asteroid shape. For our design, with spherical surfaces concentric about the center of the entrance pupil, the focal line remains unchanged in off-axis illumination.
Place, publisher, year, edition, pages
SPIE - International Society for Optical Engineering, 2005.
, Proc. SPIE
geometrical optics, diffractive optics, axicon, lens design
Atom and Molecular Physics and Optics
IdentifiersURN: urn:nbn:se:kth:diva-62325DOI: 10.1117/12.625162OAI: oai:DiVA.org:kth-62325DiVA: diva2:480148
Optical Design and Engineering II, Gena, 13 September 2005 through 16 September 2005
QC 201201192012-01-192012-01-192012-01-19Bibliographically approved