Optical Znse Ball Lens Ball lenses are commonly used for laser collimating and focusing, laser-to-fiber coupling, fiber-to-fiber coupling, Solar-photovoltaic and fiber-to-detector coupling. Worldhawk can provide spherical ball lenses and half ball lenses in a range of substrates for performance in the ultraviolet to the NIR. Such as including H-K9L(N-BK7), Sapphire, CaF2, BaF2, ZnSe or custom materials upon request. Ball lenses feature short back focal lengths to minimize the distance needed from the ball Lens to the optical fiber. Ball lenses are commonly used to improve signal quality in fiber coupling applications, or for use in endoscopy or bar code scanning applications. Specifications of Ball Lens (Half ball lens)    Item    Parameter (Optical glass ball lens; Half ball lens)   Material   K9 (BK7), Optical sapphire(ruby) glass, fused silica, JGS1,   ZnSe,  Zns, Ge, Caf2, b270, LaF52, Schott glass   Diameter   1~150mm, 1mm, 2mm, 3mm…   Dia. Tolerance   +/-0.002mm   Roundness   0.003-0.005   Surface Accuracy   <2λ   Irregularity   λ/2 @632.8nm   Surface Quality   <40/20 scratch/dig   Clear Aperture   >92%   Focal length tolerance   +/-1% (+/-5% for 400 series)   Centration   3 arc min or better   Coating   Upon customer request Material Specifications  Glass  Materials Refractive  (nd)   Dispersion  Coefficient(vd)  Glass  Materials Refractive  (nd)   Dispersion  Coefficient(vd)   H-Zlaf90   2.00069   25.43   Sapphire   1.768   72.20   H-Zlaf50D   1.804   46.58   ZnSe   2.403   N/A   H-ZF7LA   1.80518   25.46   Silicon   3.422   N/A   Fused Silica   1.458   67.70   Germanium   4.003   N/A   H-K9L(N-BK7)   1.517   64.20         Parameters Explaination: EFL: Effective Focal Length    BFL: Back Focal Length CT  : Center Thinkness           C    : Lens Center