Optical Lenses
A Cylindrical Lens, also called a Cylinder Lens, is a special type of optical lens component that resembles the shape of a semi-cylinder (the curved side of a cylindrical lens is a section of a cylinder). Cylinder lenses are optical lenses designed with curvature along only one axis—the X or Y axis—while remaining flat along the perpendicular axis. Unlike spherical lenses that focus or diverge light into a point, a cylindrical lens focuses or diverges light into a line since it only expands or collects light in one dimension and doesn’t affect how light bends in the vertical dimension. Therefore, cylindrical lenses are ideal for applications like laser line generation, anamorphic beam shaping, and astigmatism correction in imaging systems where light manipulation in only one dimension is necessary.
There are several types of cylindrical lenses, including Plano Convex Cylindrical Lenses, Plano Concave Cylindrical Lenses, Fast Axis Collimators, and Slow Axis Collimators. A plano-convex cylindrical lens (also known as a positive cylindrical lens) consists of a flat surface and an outwardly curved surface. A plano convex cylinder lens has a positive focal length and converges light in one dimension (line-focusing). A plano concave cylindrical lens (negative cylindrical lens) has one flat side and one inwardly curved side; it has a negative focal length and diverges light along one axis.
Fast axis collimators (FACs) and slow axis collimators (SACs) are specialized aspheric cylinder lenses used for high-power laser diodes, where the fast axis collimators and slow axis collimators are utilized to shape and collimate the asymmetric output beams of high-power diode bars or single emitters. Sometimes the FACs and SACs are used together to reshape the laser diode’s output into a collimated beam suitable for further optical processing (e.g., fiber coupling, beam combining, or focusing).
The applications of cylindrical lenses are manifold. The basic function of cylindrical lenses is to focus or diverge a light source into a straight line. A pair of cylindrical lenses can be used to compress or expand beam dimensions, circularizing elliptical beams where a collimated, circular laser source is required. Cylinder lenses can also be used for the modification of image height or correcting astigmatic aberrations in imaging systems. These lenses are essential in laser diode beam shaping, laser line generation, laser scanning, and optical metrology.
Hangzhou Shalom EO supplies Off-the-shelf and Custom Cylindrical Lenses. The cylinder lens optics are available in various geometries and specs, including plano-convex cylindrical lenses, plano-concave cylindrical lenses, fast axis collimators (FAC lenses), and slow axis collimators (SAC lenses). The lenses are crafted from a wide selection of optical materials, including BK7, fused silica, CaF2, BaF2, MgF2, ZnSe, etc. Anti-reflection coatings (BBAR, V-coatings, single-layer MgF2 coatings) at different wavelengths can be selected.
With tight tolerances in curvature and surface quality, Shalom EO's cylindrical lenses ensure precise line-focusing and minimal optical aberration, supporting demanding applications in laser systems, barcode readers, and imaging devices.
