The traditional manual method is adopted to process the lager diameter parabolic and hyperbolic lens with BK7 (ZK N4 or Zerodur) material, use knife-edge instrument for test, with high processing accuracy, and the diameter can be within 900mm.surface accuracy could be less than 1/40 lambda.
|Material||BK7, ZK N4 ,Zerodur ect.|
|Aspherical surface||Parabolic, Hyperbolic|
|Focal length tolerance||±2%|
|Bevel||0.25 mm × 45°|
|Coating||Metal reflection coating/Dielectric reflection coating|