Bi-convex lens element

BK7UV

The double convex lenses are designed for extremely efficient services to applications that work with almost symmetric image/object distances. They are used in focusing and imaging. The lenses are structured from UV graded fused Silica. They have a wavelength of 587.6nm with n at 1.45848. Their tolerances are diameter- +0.0/-0.1mm, thickness of centre- ±0.2mm, centering- 3 arc minutes and focal length- ±2%. The lenses have a clear aperture more than 90%, surface figure of λ/4 @ 632.8nm and bevelling of 0.2mm x 450. The surface has a 40/20 scratch-dig quality. The lenses are available in another version that is structured from BK7 grade A optical glass. While all other parameters are exactly identical to the fused silica double convex lenses, the two versions differ in surface quality values. The BK7 lenses have a surface quality of 60/40 scratch-dig. Both versions are available without any coating. However, AR coating can be incorporated on special request.