Ball Lenses
Ball lenses are used for various tasks such as improving the coupling
between optical fibers and the emitters or detectors they interface
with. Standard size lenses range from 1.0mm to 5.0mm. Custom made
sizes or special materials are also available. All Ball lenses can
be ordered with full-surface anti-reflection (AR) coating.
The effective focal length of a ball lens is given by the following
formula:
BFL=F - D/2 and EFL=nD/4(n-1)
The Numerical Aperture, NA, of a ball lens is dependent on the
focal length of the ball and on the input diameter, d.
NA = 2d(n-1)/nD |