A cylindrical lens is an optical lens with cylindrically shaped surfaces. Since the surfaces are only simply curved, light is refracted only one-dimensionally by them ( collected by a converging lens on a straight focal line instead of on a focal point as with a spherical lens ).
Cylinder lenses are used in optical metrology , laser scanning , laser diodes , acousto-optics (e.g. acousto-optic modulator ) and optical data processing to focus laser radiation on a line. Another application is the beam shaping of the typically elliptical beam profile of laser diodes into a symmetrical beam profile. Anamorphic lenses are also used for this purpose . B. find one or more cylindrical lenses application.
Rod -shaped, plano-convex cylinder lenses made of acrylic glass ( reading rulers ) can be used as a reading aid ; they are placed with the flat side on the text and shifted line by line. People with poor eyesight can see the letters much larger (but slightly distorted) and at the same time do not lose the line so easily when changing lines.
Widescreen cinema projectors and film cameras contain a cylindrical lens in order to map the image in widescreen format onto the normal image format of the cinema film in a space-saving manner and to rectify it again during projection ( anamorphic methods such as CinemaScope , Panavision , Totalvision and similar).
Also Fresnel lenses can be formed as cylindrical lenses.
- Heinz Haferkorn: Optics. Physical-technical basics and applications . 4th, revised and expanded edition. Wiley-VCH, Weinheim 2003, ISBN 3-527-40372-8 , pp. 250 ( limited preview in Google Book Search).
- H. Daniel : Physics . tape 3 : optics, thermodynamics, quanta . Walter de Gruyter, Berlin et al. 1998, ISBN 3-11-014630-4 , p. 60 ( limited preview in Google Book search).