Double-Concave Lenses (Biconcave Lenses)
1.Diameter Tolerance +0.0, -0.15mm
2.Focal Length +/-3%
3.Centration <3 arc minutes
4.Clear Aperture >90%
5.Surface Figure λ/4 632.8nm
6.Surface Quality 40-20 scratch & dig
7.Design wavelength 632.8 nm
8.AR coatings None.