N-BK7 Plano-Concave Lenses with both surfaces AR Coating 1000-1700nm
These Plano-Concave lenses, which are fabricated from RoHS-compliant N-BK7 glass, have a broadband antireflection coating for the 1050 - 1700 nm range. This coating greatly reduces the 4% losses per surface incurred when using an uncoated lens.
N-BK7 is one of the most common types of 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.
These lenses, like all plano-concave 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 or H-K9L
||350 nm - 2.0 µm
|Focal Length Tolerance
|Index of Refraction@ 633 nm
|Surface Flatness(Plano Side)
|Spherical Surface Accuracy (Concave Side)
|Surface Irregularity(Peak to Valley)
||vd = 64.17