Cylindrical lenses are either circular or rectangular objects with cylindrically shaped surfaces. They're different with spherical lenses because they focus a beam into a focal line rather than a focal point.
High transmission is improved by an anti-reflection coating on both sides. Cylindrical lenses can be made from ZnSe, Ge, Silicon and other IR materials.
Applications include laser scanners, laser diode systems, spectrophotometers, projectors, and optical data storage and retrieval systems.