Ball lenses made of LaSFN9 glass, for coupling light into optical fibers, have an index of refraction of 1.850, offering a shorter focal length than lenses made of the common BK7 glass. The lenses are available uncoated or with a broadband near-infrared antireflection coating, in 10 diameters from 1 to 10 mm, with diameter tolerances of +0/-3 µm. Sphericity is to 0.4 µm or better, while surface quality is 40-20.
Edmund Industrial Optics
Barrington, NJ