Cylinder Lenses

Lenses with Optical Power in One Axis

 

Tightly Controlled Optical and Geometric Tolerances

 

Rectangular and Circular Form Factors Available

 

3 Performance Tiers Available: Illumination, Imaging, Beam Shaping

 

In-House Design and Coating Capabilities for Custom Requests

 

In Stock for Immediate Delivery

 

N-BK7, UV Fused Silica, and N-SF5 Substrates Available

Cylinder lenses are crucial to a wide range of laser applications including circularizing elliptical beams from a laser diode, focusing a diverging beam onto a linear detector array, creating a light sheet for measurement systems, or projecting a laser line onto a surface. They are similar to spherical lenses in the sense that they use curved surfaces to converge or diverge light, but cylinder lenses have optical power in only one dimension and will not affect light in the perpendicular dimension. Edmund Optics® is a premier provider of cylinder lenses including achromatic, acylindrical, plano-convex, and plano-concave lens geometries.

Common Applications

The three most common applications of cylinder lenses include forming a laser line, forming a laser sheet, and circularizing an elliptical laser beam.

Collimated light and a PCX cylinder lens
x =  (
d
EFL
) L

working distance: EFL + L

Collimated light and a PCV cylinder lens
x =  (
d
EFL
) (L + EFL)

working distance: L

Laser Line

A laser and a single cylinder lens can be used to create a laser line diverging across a single axis with a given fan angle θ.

Laser Line

The most important parameters when forming a laser line are the length of the line x and the working distance, or distance from the lens to the line. The equations for characterizing the laser line that will be formed depends on whether the cylinder lens used is plano-convex or plano-concave.

Figure 1 (left, top): Collimated light and a PCX cylinder lens
Figure 2 (left, bottom): Collimated light and a PCV cylinder lens
Two PCX cylinder lenses used to form a light sheet

Light Sheet

A light sheet with different divergence angles in two axes can be formed using a collimated light source and two cylinder lenses with different focal lengths. The ratios of the focal lengths should be approximately equivalent to the ratio of the height and width or the X- and Y-axis divergence angles of the desired light sheet. The same equations for laser lines are used, but now the X- and Y- axes will each follow a separate equation. The lenses must be oriented so that the curved surface of each lens is facing the light source and the planes of curvature are 90 degrees apart.

Figure 3: Two PCX cylinder lenses used to form a light sheet
Two PCX cylinder lenses forming a light sheet

Circularize an Elliptical Beam

A laser diode with no collimating optics will diverge in an asymmetrical pattern. A spherical optic cannot be used to produce a circular collimated beam as the lens acts on both axes at the same time, maintaining the original asymmetry. An orthogonal pair of cylinder lenses allows each axis to be treated separately.

To achieve a symmetrical output beam, the ratio of the focal lengths of the two cylinder lenses should match the ratio of the X and Y beam divergences. The diode is placed at the focal point of both lenses; the separation between the lenses is therefore equal to the difference of their focal lengths. The maximum beam width at each lens can be calculated using the following equation:

d =  2f(tan(
θ
2
))

By using the focal length of the lens (f) and the divergence angle of the axis it is collimating (θ), the maximum beam width (d) can be calculated. The clear aperture of each lens must be larger than the corresponding maximum beam width.

Figure 4: Two PCX cylinder lenses circularizing an elliptical beam

Selection Guide

Edmund Optics® offers Cylinder Lenses 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°, NIR I, or NIR II. Achromatic Cylinder Lenses provide additional color correction by minimizing chromatic aberration. Full prescription data is available for download, in addition to 2D or 3D models.

Product FamilyWavefront ErrorSurface QualityWedge ToleranceProduct BreadthChromatic CorrectionPrice
Illumination Cylinder Lenses Undefined
GOOD
Undefined
Absolute Best
No
 
Imaging Cylinder Lenses
BETTER
GOOD
BETTER
BETTER
No
  
Beam Shaping Cylinder Lenses
BEST
BEST
BEST
BEST
No
   
Acylinder Lenses
BETTER
GOOD
GOOD
GOOD
No
     
Achromatic Cylinder Lenses
GOOD
BETTER
BETTER
GOOD
Yes
    
Illumination Cylinder Lenses
Illumination Cylinder Lenses

Illumination Cylinder Lenses are the most economical option EO offers and have the most options for size and focal length; but they don’t have as tight performance tolerances. They are ideal for cost-sensitive illumination applications. View Product

Pros:

  • Wide selection of sizes and focal lengths
  • Most cost-effective option

Cons:

  • Undefined wavefront specification
  • Limited geometric tolerancing
Imaging Cylinder Lenses
Imaging Cylinder Lenses

Imaging Cylinder Lenses have better wavefront error and wedge tolerances than Illumination Cylinder Lenses, but they have the same surface quality and fewer size and focal length options. They are ideal for generating laser lines and laser sheets. View Product

Pros:

  • Balance of performance and price

Cons:

  • Size limited to 10 x 20mm and below
Beam Shaping Cylinder Lenses
Beam Shaping Cylinder Lenses

Beam Shaping Cylinder Lenses are an optimal pairing of tightly controlled tolerances and optimal pricing for volume integration. They are ideal for beam shaping applications such as circularizing elliptical beams from a laser diode, creating a light sheet for measurement systems, or projecting a laser line onto a surface. View Product

Pros:

  • Tightly controlled optical tolerances including wavefront error, surface quality, and wedge
  • Tightly controlled geometric tolerances of plano axis wedge, power axis wedge, and axial tilt
  • Ideal combination of price and quality

Cons:

  • More expensive than Illumination Cylinder Lenses
Acylinder Lenses
Acylinder Lenses

Acylinder Lenses have an aspheric surface that greatly reduces spherical aberration. They feature diffraction limited performance and are ideal for creating thin line profiles of monochromatic light sources. View Product

Pros:

  • Diffraction limited design allows them to create extremely sharp, thin laser lines

Cons:

  • Most expensive cylinder lens option
  • Subject to severe spherochromatism
Achromatic Cylinder Lenses
Achromatic Cylinder Lenses

Achromatic Cylinder Lenses consist of a positive low-index (crown) element and a negative high-index (flint) element cemented together to minimize chromatic and spherical aberration. They are ideal for use with broadband light sources due to their color correction. View Product

Pros:

  • Chromatic aberration correction allows for use with broadband light sources
  • Spherical aberration correction allows for creation of thin laser lines

Cons:

  • More costly than most cylinder lens options
  • Limited options for size and specifications

FAQ's

FAQ  What wavelength range do EO’s cylinder lenses cover?
Multiple anti-reflection coating options are available from the ultraviolet to the infrared covering wavelengths from 250nm to 1550nm, including UV-AR, UV-VIS, MgF2, VIS-NIR, VIS 0°, NIR I, or NIR II. Uncoated lenses are also available covering wavelengths from 200nm to 2500nm.
FAQ  What lens substrate materials are available?

EO offers cylinder lenses made of optical glasses including N-BK7, UV Fused Silica, N-SF5, and N-SF11..

FAQ  What is the difference between an achromatic cylinder lens and a standard plano-convex (PCX) cylinder lens?

PCX cylinder lenses only use one substrate material and achromatic cylinder lenses use multiple substrates to correct for spherical and chromatic aberration. Achromatic cylinder lenses are ideal for applications requiring magnification in only one dimension where a thin line profile is essential. They offer several performance advantages compared to traditional cylinder lenses, including superior reduction of spherical and chromatic aberration at the image plane. When used with a LED source, Achromatic Cylinder Lenses are ideal for line generation. Typical applications include line generation with LED illumination sources and superior focusing with LED-based scanning devices. The illustration below compares a focused line with an Achromatic Cylinder Lens and one with a standard plano-convex (PCX) cylinder lens.

FAQ  Is it better to use a cylinder lens or an anamorphic prism pair to circularize elliptical beams?
Both anamorphic prism pairs and cylinder lenses can be used to achieve single axis beam modulation. There are a few practical differences between them:
  • Anamorphic prism pairs take up less space
  • Cylinder lenses may affect the radiance profile of the beam due to aberrations
  • Cylinder lenses do not displace the beam

Resources

Application Notes

Technical information and application examples including theoretical explanations, equations, graphical illustrations, and much more.

Considerations when Using Cylinder Lenses
Read  

What Are Cylinder Lenses?
Read  

Why Choose an Achromatic Cylinder Lens?
Read  

Videos

Informative corporate or instructional videos ranging from simple tips to application-based demonstrations of product advantages.

Cylinder Lens Product Overview
Watch