N-BK7 Plano-Concave Lenses, Uncoated
|Lens Shape||Plano / Concave|
|Substrate Material||N-BK7 (Grade A)|
|Wavelength Rangea||350 nm - 2.0 µm|
|Diameters Available||6 mm, 9 mm, 1/2",|
25 mm, 1", or 2"
|Diameter Tolerance||+0.0/-0.1 mm|
|Thickness Tolerance||±0.1 mm|
|Focal Length Tolerance||±1%|
|Design Wavelength||587.6 nm (Except Ø25 mm Lenses)|
632.8 nm (Ø25 mm Lenses)
|Index of Refraction|
|Surface Quality||40-20 Scratch-Dig|
|Spherical Surface Power|
(Peak to Valley)
|Clear Aperture||>90% of Diameter|
- Material: N-BK7
- Wavelength Range: 350 nm - 2.0 μm (Uncoated)
- Choose from 6 Diameters: Ø6 mm, Ø9 mm, Ø1/2" (Ø12.7 mm), Ø25 mm,
Ø1" (Ø25.4 mm), or Ø2" (Ø50.8 mm)
- Offers Excellent Transmittance Throughout the Visible and Near Infrared
These Plano-Concave lenses are fabricated from RoHS-compliant N-BK7 glass. N-BK7 is probably the most common optical glass used for high quality 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. However, for particularly harsh environments where the optic will be exposed to alkalis and acids, consider our N-SF11 plano-concave lenses.
Like all plano-concave lenses, these lenses have negative focal lengths and can be used to diverge collimated beams. In this case, the curved surface of the lens should face the source to minimize spherical aberration. In addition, they can be employed to offset the effects of spherical aberration caused by other lenses in an optical system.
N-BK7 lens kits are also available. Please click here for information.
Below is the transmission curve for N-BK7, a RoHS-compliant form of BK7. Total Transmission is shown for a 10 mm thick, uncoated sample and includes surface reflections.
Click Here for Raw Data
Click to Enlarge