As the name suggests, a cylindrical lens or cylinder lens is an optical lens with a cylindrical or semi-cylindrical shape. Like a spherical lens, a cylindrical lens has one curved and one flat side. Unlike a spherical lens, however, cylindrical lenses aren’t fully symmetrical — the orientation of a cylindrical lens affects how it transmits light.
When you’re considering a cylindrical lens versus a spherical lens, the most important distinction is where the lens brings light into focus. A spherical lens brings beams of light to focus at a single point for viewing. A cylindrical lens, by comparison, focuses light onto a line. This change happens because light comes into focus at different points depending on where on the axis it enters the lens. All the focus points line up exactly, producing a horizontal or vertical line of light, depending on the lens orientation.
Through this type of one-dimensional amplification, cylinder lenses effectively correct spherical and chromatic aberrations. As a result, cylindrical lenses are widely used to correct ocular astigmatism and change image size.
Aspheric Cylindrical Lens
Cylinder lenses are optical lenses with different radii on the x and y axis. These lenses are often used to correct for astigmatism in imaging systems, and are also ideal for beam shaping, to adjust image height size, or as a laser line generator. Like spherical lenses, these lenses may have one curved and one flat side or two curved sides. The curved face or faces of a cylindrical lens are portions of a cylinder, and the lens focuses light in a single dimension; i.e., into a line rather than into a point.
As light passes through the face of a cylindrical lens, it travels into a line parallel to the intersection of the surface of the lens and a plane tangent to that. The image is unchanged in the direction of this tangent plane, but is compressed in the direction perpendicular to it.
Cylindrical lenses are typically square, circular, or rectangular. Shanghai Optics produces a line of cylindrical lenses in plano convex, plano concave, or aspheric shape. Special lenses available on request include bi-convex or double concave cylindrical lenses, parabolic mirrors, cylindrical ellipsoidal mirrors and double curved cylindrical lenses. Off-axis cylindrical mirrors, angled cylindrical mirrors, or fan shaped lenses can also be manufactured to meet a custom order.
Substrate options include Schott or Ohara glass, CDGM, Corning Fused Silica, JGS1 or JGS2. The surface quality of our cylindrical lenses is 20-10 after coating, and the clear aperture is greater than 90 percent of the central dimension.
A plano convex cylindrical lens, also known as a positive cylindrical lens, will condense light on one axis. It can be used to magnify an image in one direction, changing the aspect ratio. They will focus collimated light to a line, or to create a line image from a point of light. These lenses are used for such applications as laser projection and illuminating slit and line detector arrays. Two plano convex cylindrical lenses can be used to collimate and circularize the light emitted from a laser diode.
A plano convex lens should be oriented so that light is incident on the curved surface if you are focusing to a line. When collimating light, orient your lens so that the light from your line source is incident on the plano surface.
Plano concave cylindrical lenses are called negative cylindrical lenses. They are similar to plano concave lenses, but act only on one axis. They can expand light on this single axis, and diverge collimated input light away from a line. Our negative cylindrical lenses can be used for laser line generation, one-dimensional image compression, or anamorphic beam shaping. The curved surface of a negative cylindrical lens should face the source when it is used to diverge a beam, or aberration may become a problem.
An aspheric cylindrical lens is to a cylindrical lens what an aspheric lens is to a standard spherical lens. Designed to reduce aberration, they provide the same one dimensional focusing a conventional cylindrical lens does. Their form is slightly deviated from that of a true cylinder, and they are used in applications similar to those of other cylindrical lenses: anamorphic beam shaping, collimating the output of a laser diode, or focusing a diverging beam on a detector array.
The main significance of a cylinder lens is its ability to focus light onto a continuous line rather than a fixed point. This quality gives the cylindrical lens various unique abilities, such as laser line generation. Some of these applications simply aren’t possible with a spherical lens. Cylindrical lens capabilities include:
Cylindrical lenses find use in a wide range of industries. Common applications for cylindrical optical lenses include detector lighting, bar code scanning, spectroscopy, holographic lighting, optical information processing and computer technology. Because applications for these lenses tend to be highly specific, you may need to order custom cylindrical lenses to achieve the desired results.
Shanghai Optics can produce a variety of specifications and different radii, using different glass material (Schott, Ohara, CDGM, Fused Silica, MgF2, CaF2, ZnSe, ZnS etc.). Examples are: Plano-Convex Cylindrical lens, Plano-Concave Cylindrical lens, Bi-Convex Cylindrical lens, Double Concave Cylindrical lens, Meniscus Cylindrical lens. We also can produce special Cylindrical lenses, such as Achromatic Cylindrical lens, Parabolic Mirrors, Cylindrical Ellipsoidal Mirror and double curved Cylindrical lens, such as Aspheric Cylindrical lens and Cylindrical lens group. In addition, we even can produce the requirements of complex shape Cylindrical lenses, such as fan-shaped lenses, the Off-Axis Cylindrical Mirrors, angled Cylindrical Mirrors. Requests can include special Glass materials including ultraviolet and infrared quartz; or crystals like fluorinated calcium.
Shanghai Optics has acquired custom made CGH Cylinder Nulls for most F/#’s and apertures for cylindrical lenses testing. Combined with our Zygo interferometer, Shanghai Optics can measure and provide interferogram and inspection reports in the most precise fashion.
The video above is a short clip on cylindrical lens testing. Shanghai Optics has acquired custom made CGH Cylinder Nulls for most F/#’s and apertures for cylindrical lens testing. Combined with our Zygo Verifire Interferometer, we can deliver high precision customized cylindrical lenses for your specific application.
|Specifications||Factory Standards||Manufacturing Limit|
|Center Thickness Tolerance||+/-0.03 mm||+/-0.02mm|
|Irregularity(Plano Surface)||1/8Lambda||< 1/15Lambda|
|Irregularity(Cylindrical Surface)||1/4Lambda||< 1/8Lambda|
Contact us for manufacturing limit or custom specifications.
Cylinder lenses generally take more effort to produce than spherical lenses, though both types require great precision. The lenses are made of optical glass and are either molded or cut out of a cylinder to your specifications. The lenses are then polished, coated and examined for proper power and performance.
Producing a cylindrical lens with the proper measurements can take a lot of time, which is why Shanghai Optics uses high-speed polishers that allow us to produce lenses 10 times faster than those using traditional polishing methods. With speed, precision and high quality-control standards, S.O. has the ability to manufacture custom cylindrical lenses to meet a variety of specific needs.
We can manufacture cylinder lenses with different types of glass, different radii and custom shapes. We can also craft special types of lenses, including achromatic cylindrical lenses, parabolic mirrors, cylindrical ellipsoidal mirrors and double curved cylindrical lenses.
Many projects require custom optical lenses, and for cylinder lenses, customization is the norm rather than the exception. After all, in order to achieve the desired results, a cylindrical lens must match the exact dimension and specifications necessary to project a line of the proper length and focal distance.
If you’re looking for a manufacturer that can produce custom cylindrical lenses to your exact specifications, Shanghai Optics would make a strong choice. We have more than 55 years of experience designing, manufacturing and refining custom optical lenses for use in a range of industries. Our production staff follows strict ISO 9001 standards and uses state-of-the-art metrology equipment to test finished lenses for quality and performance.
Choose from N-BK7 glass, UV fused silica, or CaF2 ,or other special materials specified by customers, all of which are available uncoated or with an antireflection coating with surface accuracy up to λ/8 and surface quality up to 10-5.
To learn how S.O. could assist with your current optics project, request a quote online or contact one of our friendly representatives for more information.