Custom Meniscus Lens Positive And Negative Meniscus Lenses

Meniscus Lens can increase the NA of the system while only adding slightly to the total spherical aberrations. The Negative Meniscus Lens is used to increase the focal length of another lens while maintaining the angular resolution of the optical assembly. This lens shape is best used when one conjugate is relatively far from the lens. Material:                        Optical Glass Surface Flatness:                < λ/5 @ 633nm Scratch/Dig:                     < 40/20 (both sides) Eccentricity:                     ≤ 1arcmin Focal Length Tolerance           < ± 1% Diameter Tolerance:              < + 0.00/ - 0.10mm Thickness Tolerance:             < ± 0.1 Clear Aperture:                  ≥ 90% of diameter Coating:                       AR OR BBAR Diameter Range:               5~260mm