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Knight Optical(UK) Ltd - [email protected] - +44 (0)1622 859444

BK7/SF11 concave lenses

What are you looking for in Stock?

This range of lenses is of the plano-concave variety. These lenses consist of one inward curved face and one flat face. The main attribute of a plano-concave lens is to bend the parallel input rays so that they diverge away from one another on the output side. This type of lens is widely used within image reduction or to spread light.  Plano-concave lenses are typically used for beam expanders. Plano-concave lenses are also known as a tube-length correction lens in microscopy and as a barlow lens in astronomy. The Plano-concave lenses stocked here are our high quality grade BK7/SF11 type or equivalent.  Knight Optical stock a range of high quality plano-concave lenses which are uncoated or AR coated.  Antireflective coated versions have a multilayer AR coating for 450-900nm.


Material: N-BK7 or equivalent, SF11 or equivalent (for lower spherical aberrations)
Diameter: +0.0 / -0.10mm
Centration accuracy: < 5 arcmin
Focal length (@587nm): ± 0.2mm (≤10mm) ± 2.0% (>10mm)
Centre thickness: ± 0.15mm
Surface quality: <40-20 scratch/dig

Planoconcave lenses with suffix "AV2" are coated on both faces with:
multilayer antireflective coating <0.5%@450-900nm

  • Mounting into lens cells.
  • Special AR coating to meet visible and NIR telecoms applications.
  • Stock lenses can be edged to smaller diameters.

Planoconcave lenses with suffix "AV2" are coated on both faces with:
multilayer antireflective coating <0.5%@450-900nm
except SF11 which are coated on both faces with:
single layer MgF² antireflective coating <0.2%@550nm

Stock Optics

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Part No. CoatingFocal Length
Material Price
LNQ10025 Uncoated100.025.0N-BK7 or equivalent £15.95
LNQ5012 Uncoated50.012.5N-SF11 or equivalent £15.95
LNQ1006 Uncoated10.06.0N-SF11 or equivalent £13.95
LNQ2010 Uncoated20.010.0N-SF11 or equivalent £15.95
LNQ12525 Uncoated125.025.0N-BK7 or equivalent £15.95
LNQ100025 Uncoated1000.025.0N-BK7 or equivalent £15.95
LNQ1512 Uncoated15.012.5N-SF11 or equivalent £15.95
LNQ20025 Uncoated200.025.0N-BK7 or equivalent £15.95
LNQ50025 Uncoated500.025.0N-BK7 or equivalent £15.95

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Get in touch

Our Multi-Lingual Sales Team are here to help with your requirments:

UK +44 (0)1622 859444
UK +44 (0)1622 850614
UK +44 (0)1622 851078
+1 401 583 7846

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