Cylinder Lenses are typically used to focus incoming light to a line, or to change the aspect ratio of an image. Cylindrical Lenses have a single cylindrical surface that causes incoming light to be focused in only a single dimension, stretching the image. Cylinder Lenses are available with positive or negative focal lengths, ideal for laser line generation or anamorphic beam shaping to circularize laser outputs.
Edmund Optics selection of Cylinder Lenses include achromatic, acylinder, plano-convex, or plano-concave. Achromatic Cylinder Lenses provide additional color correction by minimizing chromatic aberration. Hybrid Acylinder Lenses are ideal for color correction, in addition to minimizing spherical aberration. Edmund Optics offers Cylinder Lenses with glass or plastic substrates, or with circular, rectangular, or oblong dimensions. Multiple anti-reflection coating options are available from the ultraviolet to the infrared, including UV-AR, UV-VIS, MgF2, VIS-NIR, VIS 0°, or NIR I. Edmund Optics offers full prescription data, in addition to 2D or 3D models.
Cylinder lenses are ideal for circularizing elliptical beams from a laser diode, creating light sheets for microscopy or measurement systems, and projecting a laser line onto a surface. As opposed to spherical lenses which focus light in two dimensions, cylinder lenses are used to focus light in one dimension. A cylinder lens in its most basic form is a subsection of a cylinder glass. The outside of the cylinder is the powered or curved optical surface. These lenses often have one powered surface paired with a plano surface providing additional flexibility in manufacturing and testing options. Cylinder lenses differ from spherical lenses because of their geometrical shape, and because of this, additional specifications need to be considered, including power axis, plano axis, and axial twist. Let’s consider power axis wedge, otherwise known as decenter. This error is similar to the decenter of the spherical lens, where there is a displacement of the curved optical surface relative to the optical axis. This error is typically specified by an angle or by edge thickness difference, often denoted by ETD. As we examine the plano axis, we see that there is a rectangular profile of the cylinder lens which looks like a flat optic. Much like wedge, also referred to as parallelism in a mirror filter or window, we see a displacement of one surface relative to the other. In the case of the cylinder lens, the wedge occurs between the power and plano optical surfaces as seen here. Axial twist on the other hand can only occur when we have a rectangular cylinder lens. This is a rotation of the powered surface relative to the side of the lens. When axial twist is present in a lens, it produces a rotation of the focal plane about the about the optical axis. In a circular cylinder lens, there is no edge to act as a hard reference, so all axial twist is organically removed from the system. Theses errors manifest in a myriad of optical aberrations and there is an increase of importance when considering a multi element systems. The key to minimizing these aberrations is understanding the correct specifications in order to tolerance your system accordingly. For more information on cylinder lenses, visit https://www.edmundoptics.com/.