Cylindrical Lenses

Cylindrical lenses have different radii in the x and y axes, they are similar to spherical lenses in the sense that they use curved surfaces to converge or diverge light, but cylinder lenses have optical power in only one dimension and will not affect light in the perpendicular dimension. Cylinder Lenses have a single cylindrical surface that causes incoming light to be focused in only a single dimension, i.e., into a line rather than into a point, or changes the aspect ratio an image in only a single axis. Cylindrical lenses have square, circular, or rectangular styles, like spherical lenses they are also available with positive or negative focal lengths. Cylindrical lenses are commonly used to adjust image height size, or correct for astigmatism in imaging systems, and in a wide range of laser applications including circularizing elliptical beams from a laser diode, focusing a diverging beam onto a linear detector array, creating a light sheet for measurement systems, or projecting a laser line onto a surface. Cylindrical lenses are applied in a wide range of industries including detector lighting, bar code scanning, spectroscopy, holographic lighting, optical information processing and computer technology.

Positive cylindrical lenses have one flat surface and one convex surface, they are ideal for applications requiring magnification in one dimension. While spherical lenses act symmetrically in two dimensions on an incident ray, cylindrical lenses act in the same manner but only in one dimension. A typical application would be to use a pair of cylindrical lenses to provide anamorphic shaping of a beam. Another application is to use a single positive cylindrical lens to focus a diverging beam onto a detector array; A pair of positive cylindrical lenses can be used to collimate and circularize the output of a laser diode. To minimize the introduction of spherical aberrations, collimated light should be incident on the curved surface when focusing it to a line, and light from a line source should be incident on the plano surface when collimating.

Negative cylindrical lenses have one flat surface and one concave surface, they have a negative focal length and act as plano-concave spherical lenses, except on only one axis. These lenses are used in applications that require one dimensional shaping of a light source. A typical application would be to use a single negative cylindrical lens to transform a collimated laser into a line generator. Pairs of cylindrical lenses may be used to anamorphically shape images. To minimize the introduction of aberration, the curved surface of the lens should face the source when used to diverge a beam.
Paralight Optics offers cylindrical lenses fabricated with N-BK7 (CDGM H-K9L), UV-fused silica, or CaF2, all of which are available uncoated or with an antireflection coating. We also offer round versions of our cylindrical lenses, rod lenses, and cylindrical achromatic doublets for applications requiring minimal aberration.