Aspheric Condenser Lenses with Diffuser Surface


  • Combines Aspheric Condenser with Diffuser on the Plano Side of the Lens
  • 600 Grit and 1500 Grit Versions Available
  • Uncoated or AR Coated for 350 - 700 nm or 650 - 1050 nm
  • Lenses with NA of 0.60

ACL5040U-DG15-A

(Ø50 mm)

ACL2520U-DG15

(Ø25 mm)

ACL5040U-DG6-B

(Ø50 mm)

Plano Surface of ACL5040U-DG15

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General Specifications
Substrate B270 Optical Crown Glass
Wavelength Range Uncoated: 380 - 2100 nm
A: 350 - 700 nm
B: 650 - 1050 nm
Reflectance Over AR Coating Range
for Coated Optics (Avg., AOI = 0°)
Ravg < 0.5%
Focal Length Tolerance ±8%
Design Wavelength Visible
Surface Quality (Asphere Side) 80-50 Scratch-Dig
Uncoated Transmission Graph
(Click Here to Download Raw Data)
Icon
A Coating Reflectance Graph
(Click Here to Download Raw Data)
Icon
B Coating Reflectance Graph
(Click Here to Download Raw Data)
Icon
Diameter Tolerance +0.0 mm / -0.5 mm
Center Thickness Tolerance ±0.3 mm
Centration <30 arcmin
Temperature (Max) 250 °C (482 °F)
app shot
Click to Enlarge

Light from an LED Collimated by a Non-Diffusing Condenser Lens
app shot
Click to Enlarge

Light from an LED Collimated by a Condenser Lens with a Diffuser Surface

Features

  • Combines a Condenser and a Diffuser into a Single, Compact Optic
  • 25 mm and 50 mm Diameters Available
  • 600 or 1500 Grit Polished Versions Available
  • 20 mm or 40 mm Focal Length Versions Available
  • Available Uncoated or AR-Coated for 350 - 700 nm or 650 - 1050 nm on Aspheric Surface
  • Offers Higher NA and Larger Aperture than Spherical Lenses

Thorlabs' Aspheric Condenser Lenses with Diffusers are designed for collimating light from lamps, LEDs, or similar sources into a highly uniform illumination pattern. We offer two sizes (Ø25 mm and Ø50 mm) to accommodate varying application needs. These lenses are available in either 600 grit or 1500 grit polished versions. A finer grit (e.g. 1500) has a small diffusion pattern, while a coarser grit (e.g. 120) will have a larger diffuser pattern. These aspheric condenser lenses are available uncoated for use in the 380 - 2100 nm range or with an AR coating for the 350 to 700 nm (-A Coating) or 650 to 1050 nm (-B Coating) range. For reflectance plots, please see the table to the right.

When collimating high-power LEDs with a standard lens, the structure of the source can ultimately be imaged through the lens, resulting in a highly non-uniform illumination pattern (see the top image on the right). For many applications, this is not desired. Adding a diffuser on the plano surface ensures a uniform illumination of the light source in the far field (see the bottom image on the right).

The aspheric surface is precision molded on the aspheric side and polished with 600 or 1500 grit on the plano side. Polished diffusers are advantageous over sand blasted diffusers as their surfaces have greater uniformity.

Thorlabs offers many types of mounting solutions for these lenses. Extra-thick retaining rings are available with SM1 (1.035"-40) and SM2 (2.035"-40) threading that provide extra clearance for spanner wrenches when mounting these lenses (see the Lens Mounting Guide tab for more information). Please visit our Fixed Optic Mounts Guide and Mirror Mounts Guide for possible mouting options available.

Optic Cleaning Tutorial
Optical Coatings and Substrates
Lens Tutorial
Aspheric Lens Design Variables
Click to Enlarge

Reference Drawing

Aspheric Lens Design Formula

Definitions of Variables
z Sag (Surface Profile) as a Function of Y
Y Radial Distance from Optical Axis
R Radius of Curvature
k Conic Constant
An nth Order Aspheric Coefficient

The aspheric surface of these lenses may be described using a polynomial expansion in Y, the radial distance from the optical axis. The surface profile or sagitta (often abbreviated as sag) is denoted by z, and is given by the following expression:

where R is the radius of curvature, k is the conic constant, and the An are the nth order aspheric coefficients. The sign of R is determined by whether the center of curvature for the lens surface is located to the right or left of the lens' vertex; a positive R indicates that the center of curvature is located to the right of the vertex, while a negative R indicates that the center of curvature is located to the left of the vertex. For example, the radius of curvature for the left surface of a biconvex lens would be specified as positive, while the radius of curvature for its right surface would be specified as negative.

Item # Prefixa ACL2520U ACL5040U
S1: R (mm) 10.462 20.923
k -0.6265 -0.6405
A4 1.5E-5 2.0E-6
A6 0 0
A8 0 0
A10 0 0
A12 0 0
S2b: R (mm) Plano Plano
  • Target Values
  • S2 is the non-aspheric side of the lens.

Aspheric Lens Coefficients

Due to the rotational symmetry of the lens surface, only even powers of Y are contained in the polynomial expansion above. The target values of the aspheric coefficients for each product can be found in the table to the right or by clicking on the red documents icon (docs) next to each lens sold below.

Thorlabs' retaining rings are used to secure unmounted optics within lens tubes or optic mounts. These rings are secured in position using a compatible spanner wrench. For flat or low-curvature optics, standard retaining rings manufactured from anodized aluminum are available from Ø5 mm to Ø4". For high-curvature optics, extra-thick retaining rings are available in Ø1/2", Ø1", and Ø2" sizes.

Extra-thick retaining rings offer several features that aid in mounting high-curvature optics such as aspheric lenses, short-focal-length plano-convex lenses, and condenser lenses. As seen in the animation to the right, the guide flange of the spanner wrench will collide with the surface of high-curvature lenses when using a standard retaining ring, potentially scratching the optic. This contact also creates a gap between the spanner wrench and retaining ring, preventing the ring from tightening correctly. Extra-thick retaining rings provide the necessary clearance for the spanner wrench to secure the lens without coming into contact with the optic surface.


Posted Comments:
cdolbashian  (posted 2024-08-01 12:52:33.0)
Thank you for contacting Thorlabs. Aspheric condenser lenses with diffusers are designed for collimating light from LED, 1500 grit has a small diffusion pattern but high transmittance, 600 grit has a larger diffuser pattern but low transmittance. You can select grit versions based on which parameter you value more in your experiment, diffusion pattern size or transmission intensity.
Josh Philipson  (posted 2022-02-23 08:38:56.3)
Hi, Is there a Zemax file for ACL2520U-DG6 please? Thank you, Josh
ksosnowski  (posted 2022-02-25 06:55:57.0)
Thanks for contacting Thorlabs. Unfortunately we do not have Zemax files for these lenses with diffusers attached, however we do have files for the base lens like ACL2520U-A.
john.w.easton  (posted 2018-12-13 12:44:38.303)
Is the transmission curve shown for the 600 grit or 1500 grit diffuser? I am particularly interested in the transmission of 1500 grit at 725 nm (the ACL2520 lens specifically) Thanks!
mmcclure  (posted 2019-04-01 03:47:45.0)
Hello, thank you for contacting us. The transmission curve shown is for the 10 mm thick B270 substrate. These parts transmit well at 725 nm, but note the throughput will depend on the collection method you are using.
tcohen  (posted 2013-01-03 12:16:00.0)
Response from Tim at Thorlabs to Stephan: We do not have Zemax models for these currently. We will take an empirical scan and model the surface to simulate the diffuser scatter onto the ACL2520 Zemax models.
shenze  (posted 2012-12-18 15:19:37.357)
Hello, can you provide ZEMAX or TracePro data for ACL2520-DG6-A and ACL2520-DG15-A? Thank you in advance. Stephan
tcohen  (posted 2012-03-02 18:06:00.0)
Response from Tim at Thorlabs to paul.lauria: Thank you for contacting us. I have sent you the data directly.
paul.lauria  (posted 2012-03-01 14:42:08.0)
Hi, is there a Zemax file for a ACL2520-DG6-A? Thank you.
Back to Top

Aspheric Condensers with Diffusers on Plano Surface, 600 Grit

Item # Prefixa Diameter
(mm)
Focal
Length
(mm)b
Focal Shift
(Raw Data)
f/#c Clear
Aperture
(mm)
Back Focal
Length
(mm)
Numerical
Aperture
(NA)d
Center
Thickness
(mm)
Edge
Thickness
(mm)
Non-Aspheric
Surface
Suggested
Lens Mounts
Reference
Drawing
ACL2520U-DG6 25.0 20.1 Focal Shift 0.89 >22.5 12 0.60 12.0 2.8 Plano LH1(/M) Large-Diameter Aspheric Lens Drawing
ACL5040U-DG6 50.0 40.0 Focal Shift 0.89 >45.0 26 0.60 21.0 2.6 Plano LH2(/M)
  • -A and -B coated items share the same specifications shown in the table.
  • These lenses have a focal length tolerance of ±8%. This is a manufacturing tolerance and not the wavelength dependent focal shift.
  • f/# is defined as the focal length divided by the clear aperture of the lens.
  • Numerical Aperture (NA) is calculated from the sine of the marginal ray angle. Due to the thickness of the lens, the paraxial approximation is not valid to determine the path of the marginal ray.
Based on your currency / country selection, your order will ship from Newton, New Jersey  
+1 Qty Docs Part Number - Universal Price Available
ACL2520U-DG6 Support Documentation
ACL2520U-DG6Aspheric Condenser Lens w/ Diffuser, Ø25 mm, f=20.1 mm, NA=0.60, 600 Grit, Uncoated
$21.49
Today
ACL2520U-DG6-A Support Documentation
ACL2520U-DG6-AAspheric Condenser Lens w/ Diffuser, Ø25 mm, f=20.1 mm, NA=0.60, 600 Grit, ARC: 350 nm - 700 nm
$33.85
Today
ACL2520U-DG6-B Support Documentation
ACL2520U-DG6-BAspheric Condenser Lens w/ Diffuser, Ø25 mm, f=20.1 mm, NA=0.60, 600 Grit, ARC: 650 nm - 1050 nm
$33.85
Today
ACL5040U-DG6 Support Documentation
ACL5040U-DG6Aspheric Condenser Lens w/ Diffuser, Ø50 mm, f=40 mm, NA=0.60, 600 Grit, Uncoated
$52.56
Today
ACL5040U-DG6-A Support Documentation
ACL5040U-DG6-AAspheric Condenser Lens w/ Diffuser, Ø50 mm, f=40 mm, NA=0.60, 600 Grit, ARC: 350 nm - 700 nm
$64.74
Today
ACL5040U-DG6-B Support Documentation
ACL5040U-DG6-BAspheric Condenser Lens w/ Diffuser, Ø50 mm, f=40 mm, NA=0.60, 600 Grit, ARC: 650 nm - 1050 nm
$64.74
Today
Back to Top

Aspheric Condensers with Diffusers on Plano Surface, 1500 Grit

Item # Prefixa Diameter
(mm)
Focal
Length
(mm)b
Focal Shift
(Raw Data)
f/#c Clear
Aperture
(mm)
Back Focal
Length
(mm)
Numerical
Aperture
(NA)d
Center
Thickness
(mm)
Edge
Thickness
(mm)
Non-Aspheric
Surface
Suggested
Lens Mounts
Reference
Drawing
ACL2520U-DG15 25.0 20.1 Focal Shift 0.89 >22.5 12 0.60 12.0 2.8 Plano LH1(/M) Large-Diameter Aspheric Lens Drawing
ACL5040U-DG15 50.0 40.0 Focal Shift 0.89 >45.0 26 0.60 21.0 2.6 Plano LH2(/M)
  • -A and -B coated items share the same specifications shown in the table.
  • These lenses have a focal length tolerance of ±8%. This is a manufacturing tolerance and not the wavelength dependent focal shift.
  • f/# is defined as the focal length divided by the clear aperture of the lens.
  • Numerical Aperture (NA) is calculated from the sine of the marginal ray angle. Due to the thickness of the lens, the paraxial approximation is not valid to determine the path of the marginal ray.
Based on your currency / country selection, your order will ship from Newton, New Jersey  
+1 Qty Docs Part Number - Universal Price Available
ACL2520U-DG15 Support Documentation
ACL2520U-DG15Aspheric Condenser Lens w/ Diffuser, Ø25 mm, f=20.1 mm, NA=0.60, 1500 Grit, Uncoated
$21.49
Today
ACL2520U-DG15-A Support Documentation
ACL2520U-DG15-AAspheric Condenser Lens w/ Diffuser, Ø25 mm, f=20.1 mm, NA=0.60, 1500 Grit, ARC: 350 nm - 700 nm
$33.85
Today
ACL2520U-DG15-B Support Documentation
ACL2520U-DG15-BAspheric Condenser Lens w/ Diffuser, Ø25 mm, f=20.1 mm, NA=0.60, 1500 Grit, ARC: 650 nm - 1050 nm
$33.85
Today
ACL5040U-DG15 Support Documentation
ACL5040U-DG15Aspheric Condenser Lens w/ Diffuser, Ø50 mm, f=40 mm, NA=0.60, 1500 Grit, Uncoated
$52.56
Today
ACL5040U-DG15-A Support Documentation
ACL5040U-DG15-AAspheric Condenser Lens w/ Diffuser, Ø50 mm, f=40 mm, NA=0.60, 1500 Grit, ARC: 350 nm - 700 nm
$64.74
Today
ACL5040U-DG15-B Support Documentation
ACL5040U-DG15-BAspheric Condenser Lens w/ Diffuser, Ø50 mm, f=40 mm, NA=0.60, 1500 Grit, ARC: 650 nm - 1050 nm
$64.74
Today