Although not as widely known as convex or concave lenses, cylindrical lenses play an important role across numerous applications thanks to their distinct capabilities. This article explores the fundamentals of cylindrical lenses, shedding light on their working principles and use cases.
Cylinder Lenses
Cylindrical lenses, as the name implies, have a cylindrical shape in at least one section. Unlike spherical lenses, which evenly focus or disperse light in all directions, cylindrical lenses are designed to direct light in just one dimension. This distinctive feature makes them invaluable for applications where other lenses simply cannot deliver the required precision.
Understanding How Cylindrical Lenses Work
The unique shape of a cylindrical lens allows it to focus light from sources like lasers into a straight line. This capability to control light in a single dimension, either compressing or expanding it, makes cylindrical lenses incredibly versatile. Their design enables precise bending and focusing of light to meet the demands of specific applications.
Investigating Types of Cylindrical Lenses
- Singlet, Doublet, and Triplet: Cylindrical lenses with one, two, or three lens parts.
- Plano-Convex and Plano-Concave Lenses: With flat faces and convex or concave cylindrical surfaces.
- Sphero-Cylindrical Lens: Merging a sphere-like surface with a cylindrical one.
- Biconvex or Biconcave Lens: Where both sides are either concave or convex.
- Achromatic Cylinder Lens: Built to diminish chromatic aberration, concentrating light with several colors in a single direction.
Applications of Cylindrical Lenses
- Correcting Astigmatism: Aligning with the direction of astigmatism to concentrate light in a single plane and rectify distorted or blurred images.
- Laser Beam Shape Correction: Reshaping laser beams, particularly in semiconductor lasers, for enhanced quality and circular profiles.
- Optical Spectroscopy: Regulating spatial and spectral characteristics of light in spectroscopy use cases, like monochromators.
- Laser Line Scanning: Shaping laser beams into straight lines for use cases like 3D metrology and quality control.
- Microscopy: Improving confocal microscopy by shaping laser beams, rectifying aberrations, and enhancing signal-to-noise ratios in fluorescence microscopy.
Figure 1. Typically, laser diodes emit light with an elliptical profile that requires correction. Image Credit: Shanghai Optics
Materials Used to Build Cylindrical Lenses
Cylindrical lenses are available in different materials, such as fused silica (JGS1, Corning 7980, JGS2), optical glass (BK7, B270, H-K9L from Ohara, Schott, CDGM, or Corning), IR materials (MgF2, Ge, CaF2, Si), and other options such as optical plastics and sapphire.
Factory Standard
- Substrate Material: Schott, Ohara, CDGM, Corning Fused Silica and JGS1, JGS2
- Shape: P-Concave, P-Convex or Aspheric
- Focal length: +/-1 %
- Surface Quality: 20-10 (after coating)
- Surface figure: l/4 @ 633 nm
- Angle: +/-5″
- Clear Aperture: >90 % of central dimension
Source: Shanghai Optics
| Specifications |
Factory Standards |
Manufacturing Limit |
| Dimension Tolerance |
+/-0.03 mm |
+/-0.01 mm |
| Center Thickness Tolerance |
+/-0.03 mm |
+/-0.02 mm |
| Radius Tolerance |
+/-0.3 % |
+/-0.1 % |
| Surface Quality(S/D) |
40-20 |
10-5 |
| Irregularity(Plano Surface) |
1/8Lambda |
< 1/15Lambda |
| Irregularity(Cylindrical Surface) |
1/4Lambda |
< 1/8Lambda |
| Centration(arc min) |
3′ |
1′ |
Industrial Uses of Cylindrical Lenses
Cylindrical lenses are widely used across various industries, including:
- Industrial Inspection: Integral to laser scanning systems, alignment tools, and laser processing equipment.
- Semiconductor Manufacturing: Essential for circularizing elliptical beams in wafer inspection tools and flat-panel display measurement systems.
- Entertainment: Used in digital cinema cameras and projectors to compress or stretch images for optimal visual quality.
- Life Sciences and Medical Fields: Vital in life science imaging and medical testing instruments.
These specialized optical tools play a crucial role in directing light in a single dimension, with applications ranging from correcting astigmatism in ophthalmology to shaping laser beams for enhanced performance. The variety of cylindrical lenses available highlights their importance in advancing tools and technologies across multiple fields.
Shanghai Optics specializes in delivering high-quality, custom-built cylinder lenses.
This information has been sourced, reviewed and adapted from materials provided by Shanghai Optics.
For more information on this source, please visit Shanghai Optics.