NBK7 PlanoConvex Lenses (High Power, VCoated: 633 nm)
 Positive Focal Length and Near Best Form for Infinite Conjugate Applications
 AR VCoats: 633 nm
 R < 0.25% at 633 nm
LA1509633
(Ø1")
LA1074633
(Ø1/2")
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Common Specifications  

Lens Shape  PlanoConvex 
Substrate Material  NBK7 (Grade A)^{a} 
Coating (VCoat)  633 nm 
Diameters Available  1/2" or 1" 
Diameter Tolerance  +0.00/0.10 mm 
Thickness Tolerance  ±0.1 mm 
Focal Length Tolerance  ±1% 
Surface Quality  2010 ScratchDig 
Design Wavelength  587.6 nm 
Index of Refraction @ 633 nm  1.515 
Reflectance @ 633 nm  <0.25% 
Surface Flatness (Plano Side) 
λ/2 
Spherical Surface Power^{b} (Convex Side) 
3λ/2 
Surface Irregularity (Peak to Valley) 
λ/4 
Abbe #  v_{d }= 64.17 
Centration  ≤3 arcmin 
Clear Aperture  >90% of Diameter 
Focal Length Tolerance  ±1% 
Features
 Material: NBK7
 AR VCoated: 633 nm
 Ø1/2" or Ø1" PlanoConvex Spherical Singlet Lenses
These PlanoConvex Lenses are fabricated from NBK7 glass and feature laser line Vcoats at 633 nm for use with popular highpower HeNe lasers with pulsed outputs up to 10 J/cm^{2}. NBK7 is a common optical glass that can be used for highquality optical components. It 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 planoconvex lenses are popular for many applications. They have a positive focal length and nearbestform shape for infinite and finite conjugate applications. Planoconvex lenses focus a collimated beam to the back focus and 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/(n1), where n is the index of refraction and R is the radius of curvature of the lens surface. These lenses are fabricated from NBK7, which has an Abbe Number of 64.17; this value is an indicator of the dispersion.
VCoating:
Vcoating is a multilayer, antireflective, dielectric, thinfilm coating that achieves lower reflectance over a narrower bandwidth when used within their design AOI range. Reflectance rises rapidly on either side of this minimum, giving the reflectance curve a “V” shape (see Graphs tab for performance plots). When compared to broadband AR offerings, dielectric Vcoats achieve lower reflectance over a narrower bandwidth.
With a reflectance of less than 0.25% at the coating wavelength, these lenses provide exceptionally efficient transmittance and are ideal for use with HeNe lasers, as well as applications where light is transmitted through complex optical systems. Durable and capable of withstanding up to 10 J/cm^{2 }(10 ns, 10 Hz), these Vcoated spherical singlets are also particularly wellsuited for highpower applications.
Other NBK7 PlanoConvex VCoats  

780 nm  
532 / 1064 nm 
Quick Links to Other Spherical Singlets  

PlanoConvex  BiConvex  Best Form  PlanoConcave  BiConcave  Positive Meniscus  Negative Meniscus 
Below is the transmission curve for NBK7, a RoHScompliant form of BK7. Total transmission is shown for a 10 mm thick, uncoated sample and includes surface reflections. Each NBK7 lens presented here can be ordered with a 532/1064 nm, 633 nm, or 780 nm laser line Vcoating.
Click to Enlarge
Click Here for Raw Data
VCoating
The Vcoating is a multilayer, antireflective, dielectric thinfilm coating designed to achieve minimal reflectance over a narrow band of wavelengths. Reflectance rises rapidly on either side of this minimum, giving the reflectance curve a “V” shape, as shown in the following performance plots. Thorlabs' Vcoats have a minimum reflectance of less than 0.25% per surface at the coating wavelength and are designed for angles of incidence (AOI) between 0° and 20°. Compared to our broadband AR coatings, Vcoatings achieve lower reflectance over a narrower bandwidth when used at the specified AOI.
633 nm VCoat Reflectance (AOI: 0  20°)
The plot on the right is an enlarged view of the shaded region:
Other AR Coatings
Thorlabs offers NBK7 planoconvex lenses with other Vcoatings:
 YAG VCoating (532/1064 nm)
 633 VCoating (633 nm)
 780 VCoating (780 nm)
They are also available with the broadband dielectric AR coatings whose performance is shown in the graph below. Click here to view our full selection of coatings for NBK7 planoconvex lenses.
Click to Enlarge
Click Here for Raw Data
In the thick lens equation, use the index of refraction for NBK7 at the wavelength of interest to approximate the wavelengthdependent focal length of any of the planoconvex lenses.
The focal length of a thick spherical lens can be calculated using the thick lens equation below. In this expression, n_{l} is the index of refraction of the lens, R_{1} and R_{2} are the radii of curvature for surfaces 1 and 2, respectively, and d is the center thickness of the lens.
.
When using the thick lens equation to calculate the focal length of a planoconvex lens, R_{1} = ∞ and R_{2} = R. Note that the minus sign in front of R is due to the sign convention used when deriving the thick lens equations. Therefore, via substitution, the thick lens equation becomes
.
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 planoconvex is focused. The principle plane positions of a thick lens can be calculated with the following equations:
and .
However, as with the thick lens equation, H' simplifies to zero and H" simplifies to
when used to calculate the principle plane locations of planoconvex lenses. f_{b} is the back focal length of the lens, which is often referred to as the working distance of the lens.
Recommended Mounting Options for Thorlabs Lenses  

Item #  Mounts for Ø2 mm to Ø10 mm Optics  
Imperial  Metric  
(Various)  Fixed Lens Mounts and MiniSeries Fixed Lens Mounts for Small Optics, Ø5 mm to Ø10 mm  
(Various)  Small Optic Adapters for Use with Standard Fixed Lens Mounts, Ø2 mm to Ø10 mm  
Item #  Mounts for Ø1/2" (Ø12.7 mm) Optics  
Imperial  Metric  
LMR05  LMR05/M  Fixed Lens Mount for Ø1/2" Optics 
MLH05  MLH05/M  MiniSeries Fixed Lens Mount for Ø1/2" Optics 
LM05XY  LM05XY/M  Translating Lens Mount for Ø1/2" Optics 
SCP05  16 mm Cage System, XY Translation Mount for Ø1/2" Optics  
(Various)  Ø1/2" Lens Tubes, Optional SM05RRC Retaining Ring for HighCurvature Lenses (See Below) 

Item #  Mounts for Ø1" (Ø25.4 mm) Optics  
Imperial  Metric  
LMR1  LMR1/M  Fixed Lens Mount for Ø1" Optics 
LM1XY  LM1XY/M  Translating Lens Mount for Ø1" Optics 
ST1XYS  ST1XYS/M  Translating Lens Mount with Micrometer Drives (Other Drives Available) 
CXY1A  30 mm Cage System, XY Translation Mount for Ø1" Optics  
(Various)  Ø1" Lens Tubes, Optional SM1RRC Retaining Ring for HighCurvature Lenses (See Below) 

Item #  Mount for Ø1.5" Optics  
Imperial  Metric  
LMR1.5  LMR1.5/M  Fixed Lens Mount for Ø1.5" Optics 
(Various)  Ø1.5" Lens Tubes, Optional SM1.5RR Retaining Ring for Ø1.5" Lens Tubes and Mounts 

Item #  Mounts for Ø2" (Ø50.8 mm) Optics  
Imperial  Metric  
LMR2  LMR2/M  Fixed Lens Mount for Ø2" Optics 
LM2XY  LM2XY/M  Translating Lens Mount for Ø2" Optics 
CXY2  60 mm Cage System, XY Translation Mount for Ø2" Optics 

(Various)  Ø2" Lens Tubes, Optional SM2RRC Retaining Ring for HighCurvature Lenses (See Below) 

Item #  Adjustable Optic Mounts  
Imperial  Metric  
LH1  LH1/M  Adjustable Mount for Ø0.28" (Ø7.1 mm) to Ø1.80" (Ø45.7 mm) Optics 
LH2  LH2/M  Adjustable Mount for Ø0.77" (Ø19.6 mm) to Ø2.28" (Ø57.9 mm) Optics 
VG100  VG100/M  Adjustable Clamp for Ø0.5" (Ø13 mm) to Ø3.5" (Ø89 mm) Optics 
SCL03  SCL03/M  SelfCentering Mount for Ø0.15" (Ø3.8 mm) to Ø1.77" (Ø45.0 mm) Optics 
SCL04  SCL04/M  SelfCentering Mount for Ø0.15" (Ø3.8 mm) to Ø3.00" (Ø76.2 mm) Optics 
LH160C  LH160C/M  Adjustable Mount for 60 mm Cage Systems, Ø0.50" (Ø13 mm) to Ø2.00" (Ø50.8 mm) Optics 
SCL60C  SCL60C/M  SelfCentering Mount for 60 mm Cage Systems, Ø0.15" (Ø3.8 mm) to Ø1.77" (Ø45.0 mm) Optics 
Mounting HighCurvature Optics
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 lowcurvature optics, standard retaining rings manufactured from anodized aluminum are available from Ø5 mm to Ø4". For highcurvature optics, extrathick retaining rings are available in Ø1/2", Ø1", and Ø2" sizes.
Extrathick retaining rings offer several features that aid in mounting highcurvature optics such as aspheric lenses, shortfocallength planoconvex lenses, and condenser lenses. As shown in the animation to the right, the guide flange of the spanner wrench will collide with the surface of highcurvature 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. Extrathick retaining rings provide the necessary clearance for the spanner wrench to secure the lens without coming into contact with the optic surface.
Posted Comments:  
mohamed.boudhib
(posted 20140619 09:23:23.193) I noticed that your VCoated lenses (particularly AR 1064/532) are not produced at a diameter of 2". Is it just stockout ? jlow
(posted 20140714 12:17:00.0) Response from Jeremy at Thorlabs: We do not stock the Ø2" version for these lenses. We can custom make these for you. We will contact you directly regarding this. nkaddy
(posted 20140325 19:19:22.127) I noticed that none of your Vcoated lenses come premounted, is there a reason for this? cdaly
(posted 20140325 03:40:33.0) Response from Chris at Thorlabs: We do not stock a mounted version of these lenses because we have not seen a high demand for this. These lenses can easily be mounted in 1 inch lens tube, either SM1L03 or SM1L10 depending on the optic thickness. This would not have engraving of the part number however. If this is needed we can likely provide it as a custom. I will contact directly to discuss this further. 