Create an Account  |   Log In

View All »Matching Part Numbers


Your Shopping Cart is Empty
         

Mounted N-BK7 Plano-Convex Lenses (Uncoated)


  • Positive Focal Length for Infinite Conjugate Applications
  • Ø1/2", Ø1", or Ø2" Optics in SM-Threaded Mounts

LA1256-ML

(Ø2")

LA1027-ML

(Ø1")

LA1131-ML Lens
Mounted in a KB1P
Quick-Release Mount
(KB1P Mount Sold Separately)

LA1289-ML

(Ø1/2")

Related Items


Please Wait
N-BK7 Plano-Convex Spherical Singlets
Lens Shape Plano-Convex
Substrate Material N-BK7 (Grade A)a
Wavelength Range 350 nm - 2.0 μm (Uncoated)
Design Wavelength 587.6 nm or 633 nmb
Index of Refraction 1.517 (@ 587.6 nm)
1.515 (@ 633 nm)
Surface Quality 40-20 Scratch-Dig
Surface Flatness (Plano Side) λ/2
Spherical Surface Powerc
(Convex Side)
3λ/2
Surface Irregularity
(Peak to Valley)
λ/4
Abbe Number vd = 64.17
Centration <3 arcmin
Clear Aperture Ø1/2" Lenses: >Ø11.05 mm
Ø1" Lenses: >Ø22.86 mm
Ø2" Lenses: >Ø45.72 mm
Focal Length Tolerance ±1%
  • Click Link for Detailed Specifications on the Substrate
  • See the tables below for individual lens specifications.
  • Much like surface flatness for flat optics, spherical surface power is a measure of the deviation between the surface of the curved optic and a calibrated reference gauge, typically for a 587.6 nm source, unless otherwise stated. This specification is also commonly referred to as surface fit.
Optic Cleaning Tutorial

Features

  • Material: N-BK7
  • Wavelength Range: 350 nm - 2.0 μm (Uncoated)
  • Choose from Ø1/2", Ø1", or Ø2" Optics
  • Focal Lengths from 15 mm to 2500 mm
  • Mounted in SM-Compatible Lens Cells
  • Offers Excellent Transmission Throughout the Visible and Near Infrared

These uncoated Plano-Convex Lenses are fabricated from RoHS-compliant N-BK7. N-BK7 is typically chosen whenever the additional benefits of UV fused silica (i.e., good transmission further into the UV and a lower coefficient of thermal expansion) are not necessary. These Ø1/2", Ø1", and Ø2" lenses are mounted in SM05 (0.535"-40), SM1 (1.035"-40), and SM2 (2.035"-40) compatible mounts, respectively, for compatibility with our line of SM-threaded lens tubes. Each lens tube is engraved with the item #, lens type, focal length, and an arrow pointing toward the curved surface of the lens.

Like all plano-convex lenses, these lenses have a positive focal length and near-best-form shape for infinite and finite conjugate applications. They can be employed to converge collimated beams or collimate light from a point source. To minimize the introduction of spherical aberration, a collimated light source should be incident on the curved surface of the lens when being focused and a point light source should be incident on the planar surface when being collimated.

The focal length of each lens can be calculated using a simplified thick lens equation:

f = R/(n-1),

Here n is the index of refraction and R is the radius of curvature of the lens surface. For more information, please see the Tutorial tab.

Although uncoated lenses are highlighted on this page, these N-BK7 plano-convex lenses are also available with one of three antireflective coatings (-A, -B, or -C), which reduce the amount of light reflected from each surface of the lens over the specified wavelength range. Links to each of these pages can be found in the selection guide table below. Please see the Graphs tab for coating information.

N-BK7 Plano-Convex Lens Selection Guide
Unmounted Lenses Mounted Lenses
Uncoated Uncoated
A Coating (350 - 700 nm) A Coating (350 - 700 nm)
B Coating (650 - 1050 nm) B Coating (650 - 1050 nm)
C Coating (1050 - 1700 nm) C Coating (1050 - 1700 nm)
D Coating (1650 - 3000 nm) -

Custom coatings are also available. Please contact Tech Support for a quote. N-BK7 lens kits are also available. Please click here for information.

Optical Coatings and Substrates
Lens Tutorial
Quick Links to Other Spherical Singlets
Plano-Convex Bi-Convex Best Form Plano-Concave Bi-Concave Positive Meniscus Negative Meniscus

The transmission graph below is for uncoated N-BK7. It represents total transmission through a 10 mm thick, uncoated sample, and the losses within the 350 nm to 2.0 µm wavelength range are primarily due to surface reflections.

N-BK7 Transmittance
Click to Enlarge

Click Here for Raw Data


The lenses sold on this page are also available with broadband antireflective coatings, the reflectance traces of which are shown in the graph below.

These high-performance multilayer AR coatings have an average reflectance of less than 0.5% (per surface) across the specified wavelength ranges (except for the -D coating, which provides <1.0% average reflectance) and provide good performance for angles of incidence (AOI) between 0° and 30° (0.5 NA). For optics intended to be used at large incident angles, consider using a custom coating optimized at a 45° angle of incidence; this coating is effective from 25° to 52°. The plot shown below indicates the performance of the standard coatings in this family as a function of wavelength. Broadband coatings have a typical absorption of 0.25%, which is not shown in the reflectance plots.

N-BK7 AR Coating Curves
Click Here for More Information on Thorlabs' AR Coatings

N-BK7 Index of Refraction
Click here for detailed substrate data.
In the thick lens equation, use the index of refraction for N-BK7 at the wavelength of interest to approximate the wavelength-dependent focal length of any of the plano-convex lenses.

The focal length of a thick spherical lens can be calculated using the thick lens equation below. In this expression, nl is the index of refraction of the lens, R1 and R2 are the radii of curvature for surfaces 1 and 2, respectively, and d is the center thickness of the lens.

thick lens equation

When using the thick lens equation to calculate the focal length of a plano-convex lens, R1=∞ and R2=-R. Note that the minus sign in front of R is due to the sign convention used when deriving the thick lens equations and values of R are reported in the specification tables below. Therefore, via substitution, the thick lens equation becomes:

simple thick lens equation

The focal length of the lens calculated using the simplified thick lens equation directly above is the distance between the second (back) principal plane (H") and the position at which a collimated beam incident on the curved surface of the plano-convex is focused. The principal plane positions of a thick lens can be calculated with the following equations:

principal plane equation one and Principal plane equation two

However, as with the thick lens equation, H' simplifies to zero and H" simplifies to:

Principal plane two simple

when used to calculate the principal plane locations of plano-convex lenses. fb is the back focal length of the unmounted lens, which is often referred to as the working distance. For mounted lenses, the working distance is measured from the back of the threaded housing.


Posted Comments:
sleduc  (posted 2017-12-15 15:10:54.887)
Good morning, We bought a LA1484-ML lens. The Radius of Curvature is 154,5mm. Can you tell me what is the tolerance of this radius? And more, do you have a precise measure of these lenses? Thank you. Simon Leduc
tfrisch  (posted 2017-12-15 02:01:11.0)
Hello, thank you for contacting Thorlabs. The radius-of-curvature tolerance will be ±1% like the focal length tolerance. We are able to measure the focal length of individual lenses. I will reach out to you with details about this service.

Ø1/2" Mounted N-BK7 Plano-Convex Lenses (Uncoated)

Item # Optic
Diameter
Focal
Lengtha
Diopterb Radius of
Curvature
Center
Thickness
Edge
Thickness
Back Focal
Lengtha,c
Working
Distancea
Housing Reference
Drawing
LA1540-MLe Ø1/2" 15.0 mm +66.6 7.7 mm 5.1 mm 1.8 mm 11.6 mm 8.8 mm SM05-Threaded
Mount
Plano-Convex Lens Drawing
LA1074-MLd Ø1/2" 20.0 mm +50.0 10.3 mm 4.0 mm 1.8 mm 17.3 mm 14.5 mm
LA1560-MLd Ø1/2" 25.0 mm +40.0 12.9 mm 3.5 mm 1.8 mm 22.6 mm 19.9 mm
LA1289-MLe Ø1/2" 30.0 mm +33.3 15.5 mm 3.2 mm 1.8 mm 27.8 mm 25.0 mm
LA1304-MLe Ø1/2" 40.0 mm +25.0 20.6 mm 2.8 mm 1.8 mm 38.0 mm 35.3 mm
LA1213-MLe Ø1/2" 50.0 mm +20.0 25.8 mm 2.6 mm 1.8 mm 48.1 mm 45.5 mm
LA1207-MLe Ø1/2" 100.0 mm +10.0 51.5 mm 2.2 mm 1.8 mm 98.2 mm 95.4 mm
  • The focal length tolerance is ±1%. The back focal length and working distance values here are referenced to the design focal length.
  • Reciprocal of the Focal Length in Meters
  • Specified for Unmounted Lens
  • Design Wavelength: 633 nm
  • Design Wavelength: 587.6 nm
Based on your currency / country selection, your order will ship from Newton, New Jersey  
+1 Qty Docs Part Number - Universal Price Available
LA1540-ML Support Documentation
LA1540-MLØ1/2" N-BK7 Plano-Convex Lens, SM05-Threaded Mount, f = 15.0 mm, Uncoated
$37.61
Today
LA1074-ML Support Documentation
LA1074-MLØ1/2" N-BK7 Plano-Convex Lens, SM05-Threaded Mount, f = 20.0 mm, Uncoated
$37.07
Today
LA1560-ML Support Documentation
LA1560-MLØ1/2" N-BK7 Plano-Convex Lens, SM05-Threaded Mount, f = 25.0 mm, Uncoated
$35.71
Today
LA1289-ML Support Documentation
LA1289-MLCustomer Inspired! Ø1/2" N-BK7 Plano-Convex Lens, SM05-Threaded Mount, f = 30.0 mm, Uncoated
$35.44
Today
LA1304-ML Support Documentation
LA1304-MLØ1/2" N-BK7 Plano-Convex Lens, SM05-Threaded Mount, f = 40.0 mm, Uncoated
$34.91
Today
LA1213-ML Support Documentation
LA1213-MLØ1/2" N-BK7 Plano-Convex Lens, SM05-Threaded Mount, f = 50.0 mm, Uncoated
$34.63
Today
LA1207-ML Support Documentation
LA1207-MLCustomer Inspired! Ø1/2" N-BK7 Plano-Convex Lens, SM05-Threaded Mount, f = 100.0 mm, Uncoated
$34.91
Today

Ø1" Mounted N-BK7 Plano-Convex Lenses (Uncoated)

Item # Optic
Diameter
Focal
Lengtha
Diopterb Radius of
Curvature
Center
Thickness
Edge
Thickness
Back Focal
Lengtha,c
Working
Distancea
Housing Reference
Drawing
LA1951-MLd Ø1" 25.4 mm +39.4 13.1 mm 11.7 mm 1.8 mm 17.6 mm 13.8 mm SM1-Threaded
Mount
Plano-Convex Lens Drawing
LA1027-MLd Ø1" 35.0 mm +28.6 18.0 mm 7.2 mm 2.0 mm 30.2 mm 26.4 mm
LA1131-MLd Ø1" 50.0 mm +20.0 25.8 mm 5.3 mm 2.0 mm 46.3 mm 43.7 mm
LA1608-MLd Ø1" 75.0 mm +13.3 38.6 mm 4.1 mm 2.0 mm 72.0 mm 69.5 mm
LA1509-MLd Ø1" 100.0 mm +10.0 51.5 mm 3.6 mm 2.0 mm 97.3 mm 93.5 mm
LA1986-MLd Ø1" 125.0 mm +8.0 64.4 mm 3.3 mm 2.0 mm 122.4 mm 120.1 mm
LA1433-MLd Ø1" 150.0 mm +6.7 77.3 mm 3.1 mm 2.0 mm 147.5 mm 145.2 mm
LA1708-MLd Ø1" 200.0 mm +5.0 103.0 mm 2.8 mm 2.0 mm 197.5 mm 195.4 mm
LA1461-MLd Ø1" 250.0 mm +4.0 128.8 mm 2.6 mm 2.0 mm 247.4 mm 245.5 mm
LA1484-MLd Ø1" 300.0 mm +3.3 154.5 mm 2.5 mm 2.0 mm 297.3 mm 295.5 mm
LA1172-MLd Ø1" 400.0 mm +2.5 206.0 mm 2.4 mm 2.0 mm 397.1 mm 395.6 mm
LA1908-MLe Ø1" 500.0 mm +2.0 257.5 mm 2.3 mm 2.0 mm 496.8 mm 493.0 mm
LA1978-MLe Ø1" 750.0 mm +1.3 386.3 mm 2.2 mm 2.0 mm 746.1 mm 742.3 mm
LA1464-MLe Ø1" 1000.0 mm +1.0 515.1 mm 2.2 mm 2.0 mm 995.3 mm 991.5 mm
LA1254-MLe Ø1" 1500.0 mm +0.7 775.2 mm 2.1 mm 2.0 mm 1498.6 mm 1494.8 mm
LA1258-MLe Ø1" 2000.0 mm +0.5 1033.6 mm 2.1 mm 2.0 mm 1998.6 mm 1994.8 mm
LA1259-MLe Ø1" 2500.0 mm +0.4 1292.0 mm 2.1 mm 2.0 mm 2498.6 mm 2496.2 mm
  • The focal length tolerance is ±1%. The back focal length and working distance values here are referenced to the design focal length.
  • Reciprocal of the Focal Length in Meters
  • Specified for Unmounted Lens
  • Design Wavelength: 633 nm
  • Design Wavelength: 587.6 nm
Based on your currency / country selection, your order will ship from Newton, New Jersey  
+1 Qty Docs Part Number - Universal Price Available
LA1951-ML Support Documentation
LA1951-MLØ1" N-BK7 Plano-Convex Lens, SM1-Threaded Mount, f = 25.4 mm, Uncoated
$39.23
5-8 Days
LA1027-ML Support Documentation
LA1027-MLCustomer Inspired! Ø1" N-BK7 Plano-Convex Lens, SM1-Threaded Mount, f = 35.0 mm, Uncoated
$38.42
Today
LA1131-ML Support Documentation
LA1131-MLØ1" N-BK7 Plano-Convex Lens, SM1-Threaded Mount, f = 50.0 mm, Uncoated
$37.07
Today
LA1608-ML Support Documentation
LA1608-MLØ1" N-BK7 Plano-Convex Lens, SM1-Threaded Mount, f = 75.0 mm, Uncoated
$36.52
Today
LA1509-ML Support Documentation
LA1509-MLØ1" N-BK7 Plano-Convex Lens, SM1-Threaded Mount, f = 100.0 mm, Uncoated
$35.71
Today
LA1986-ML Support Documentation
LA1986-MLØ1" N-BK7 Plano-Convex Lens, SM1-Threaded Mount, f = 125.0 mm, Uncoated
$35.71
Today
LA1433-ML Support Documentation
LA1433-MLØ1" N-BK7 Plano-Convex Lens, SM1-Threaded Mount, f = 150.0 mm, Uncoated
$35.16
Today
LA1708-ML Support Documentation
LA1708-MLØ1" N-BK7 Plano-Convex Lens, SM1-Threaded Mount, f = 200.0 mm, Uncoated
$34.91
Today
LA1461-ML Support Documentation
LA1461-MLØ1" N-BK7 Plano-Convex Lens, SM1-Threaded Mount, f = 250.0 mm, Uncoated
$34.63
Today
LA1484-ML Support Documentation
LA1484-MLØ1" N-BK7 Plano-Convex Lens, SM1-Threaded Mount, f = 300.0 mm, Uncoated
$34.63
Today
LA1172-ML Support Documentation
LA1172-MLØ1" N-BK7 Plano-Convex Lens, SM1-Threaded Mount, f = 400.0 mm, Uncoated
$34.63
Today
LA1908-ML Support Documentation
LA1908-MLCustomer Inspired! Ø1" N-BK7 Plano-Convex Lens, SM1-Threaded Mount, f = 500.0 mm, Uncoated
$34.91
Today
LA1978-ML Support Documentation
LA1978-MLCustomer Inspired! Ø1" N-BK7 Plano-Convex Lens, SM1-Threaded Mount, f = 750.0 mm, Uncoated
$34.91
Today
LA1464-ML Support Documentation
LA1464-MLCustomer Inspired! Ø1" N-BK7 Plano-Convex Lens, SM1-Threaded Mount, f = 1000.0 mm, Uncoated
$34.63
Today
LA1254-ML Support Documentation
LA1254-MLNEW!Customer Inspired! Ø1" N-BK7 Plano-Convex Lens, SM1-Threaded Mount, f = 1500.0 mm, Uncoated
$32.51
Today
LA1258-ML Support Documentation
LA1258-MLNEW!Customer Inspired! Ø1" N-BK7 Plano-Convex Lens, SM1-Threaded Mount, f = 2000.0 mm, Uncoated
$32.51
Today
LA1259-ML Support Documentation
LA1259-MLNEW!Customer Inspired! Ø1" N-BK7 Plano-Convex Lens, SM1-Threaded Mount, f = 2500.0 mm, Uncoated
$32.51
Today

Ø2" Mounted N-BK7 Plano-Convex Lens (Uncoated)

Item #aOptic
Diameter
Focal LengthbDioptercRadius of CurvatureCenter ThicknessEdge ThicknessBack Focal Lengthb,dWorking DistancebHousingReference
Drawing
LA1145-ML Ø2" 75.0 mm +13.3 38.6 mm 12.5 mm 3.0 mm 66.7 mm 62.9 mm SM2-Threaded
Mount
Plano-Convex Lens Drawing
LA1050-ML Ø2" 100.0 mm +10.0 51.5 mm 9.7 mm 3.0 mm 93.6 mm 89.8 mm
LA1384-ML Ø2" 125.0 mm +8.0 64.4 mm 8.2 mm 3.0 mm 119.6 mm 115.8 mm
LA1417-ML Ø2" 150.0 mm +6.7 77.3 mm 7.3 mm 3.0 mm 145.2 mm 141.4 mm
LA1979-ML Ø2" 200.0 mm +5.0 103.0 mm 6.2 mm 3.0 mm 195.9 mm 192.1 mm
LA1256-ML Ø2" 300.0 mm +3.3 154.5 mm 5.1 mm 3.0 mm 296.6 mm 292.8 mm
LA1725-ML Ø2" 400.0 mm +2.5 206.0 mm 4.6 mm 3.0 mm 396.0 mm 393.2 mm
LA1380-ML Ø2" 500.0 mm +2.0 257.5 mm 4.3 mm 3.0 mm 497.2 mm 493.4 mm
LA1727-ML Ø2" 750.0 mm +1.3 386.3 mm 3.8 mm 3.0 mm 747.5 mm 743.7mm
LA1779-ML Ø2" 1000.0 mm +1.0 515.1 mm 3.6 mm 3.0 mm 997.6 mm 993.8 mm
  • Design Wavelength: 633 nm
  • The focal length tolerance is ±1%. The back focal length and working distance values here are referenced to the design focal length.
  • Reciprocal of the Focal Length in Meters
  • Specified for Unmounted Lens
Based on your currency / country selection, your order will ship from Newton, New Jersey  
+1 Qty Docs Part Number - Universal Price Available
LA1145-ML Support Documentation
LA1145-MLCustomer Inspired! Ø2" N-BK7 Plano-Convex Lens, SM2-Threaded Mount, f = 75.0 mm, Uncoated
$72.23
Today
LA1050-ML Support Documentation
LA1050-MLCustomer Inspired! Ø2" N-BK7 Plano-Convex Lens, SM2-Threaded Mount, f = 100.0 mm, Uncoated
$58.98
Today
LA1384-ML Support Documentation
LA1384-MLCustomer Inspired! Ø2" N-BK7 Plano-Convex Lens, SM2-Threaded Mount, f = 125.0 mm, Uncoated
$58.71
Today
LA1417-ML Support Documentation
LA1417-MLCustomer Inspired! Ø2" N-BK7 Plano-Convex Lens, SM2-Threaded Mount, f = 150.0 mm, Uncoated
$34.91
Today
LA1979-ML Support Documentation
LA1979-MLCustomer Inspired! Ø2" N-BK7 Plano-Convex Lens, SM2-Threaded Mount, f = 200.0 mm, Uncoated
$55.73
Today
LA1256-ML Support Documentation
LA1256-MLCustomer Inspired! Ø2" N-BK7 Plano-Convex Lens, SM2-Threaded Mount, f = 300.0 mm, Uncoated
$57.63
Today
LA1725-ML Support Documentation
LA1725-MLCustomer Inspired! Ø2" N-BK7 Plano-Convex Lens, SM2-Threaded Mount, f = 400.0 mm, Uncoated
$57.90
Today
LA1380-ML Support Documentation
LA1380-MLCustomer Inspired! Ø2" N-BK7 Plano-Convex Lens, SM2-Threaded Mount, f = 500.0 mm, Uncoated
$57.90
Today
LA1727-ML Support Documentation
LA1727-MLCustomer Inspired! Ø2" N-BK7 Plano-Convex Lens, SM2-Threaded Mount, f = 750.0 mm, Uncoated
$71.15
Today
LA1779-ML Support Documentation
LA1779-MLCustomer Inspired! Ø2" N-BK7 Plano-Convex Lens, SM2-Threaded Mount, f = 1000.0 mm, Uncoated
$71.15
Today
Log In  |   My Account  |   Contact Us  |   Careers  |   Privacy Policy  |   Home  |   FAQ  |   Site Index
Regional Websites:East Coast US | Europe | Asia | China | Japan
Copyright 1999-2019 Thorlabs, Inc.
Sales: 1-973-300-3000
Technical Support: 1-973-300-3000


High Quality Thorlabs Logo 1000px:Save this Image