N-SF11 Plano-Concave Lenses, Uncoated
|Lens Shape||Plano / Concave|
|Wavelength Range*||420 nm - 2.3 μm (Uncoated)|
|Diameters Available||6 mm, 9 mm, 1/2", or 1"|
|Diameter Tolerance||+0.00/-0.10 mm |
|Thickness Tolerance||±0.1 mm |
|Focal Length Tolerance||±1% |
|Design Wavelength||587.6 nm |
|Index of Refraction |
@ 633 nm
|Surface Quality||40-20 Scratch-Dig|
|Surface Flatness |
|Spherical Surface Power |
(Peak to Valley)
|Clear Aperture||>90% of Diameter|
|Focal Length Tolerance||±1%|
*These lenses are also available with an AR coating for the 350 - 700 nm range, the 650 - 1050 nm range, or the 1050 - 1620 nm range..
**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 633 nm source, unless otherwise stated. This specification is also commonly referred to as surface fit.
- Material: N-SF11
- Wavelegnth Range: 420 nm - 2.3 μm (Uncoated)
- Choose from 4 Diameters: 6 mm, 9 mm, 1/2", or 1"
- Offers Better Chemical Resistance than N-BK7
These Plano-Concave lenses, which are fabricated from N-SF11 glass, are uncoated. N-SF11 glass, a RoHS complient version of SF11, is most commonly used in harsh environments since it is inert to biological degradation and resistant to naturally encountered chemicals, alkalis, and acids. With an uncoated wavelength range of 420 nm - 2.3 μm, N-SF11 also offers a usage range that is slightly shifted to the red compared to N-BK7, which is our RoHS-compliant BK7 glass and has an uncoated wavelength range of 350 nm - 2.0 μm. Since N-SF11 glass has a lower Abbe Number than N-BK7 glass (25.76 compared to 64.17), it is associated with more dispersion.
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.
Custom Coatings are also available. Please contact our technical support staff for a quote.
The table below lists the options for fixed lens mounts for our N-SF11 Plano-Concave Lenses. Please note that some lenses require the use of the specified adapter.