A high-accuracy lens-transmission measurement facility has been constructed
and tested. The facility uses a tuneable laser source to allow measurement
s of lens transmission at discrete monochromatic wavelengths in the range 2
00 nm to 10 mum. Lenses of focal lengths from 300 mm to 750 mm can be measu
red to between 1 part in 10(4) and 1 part in 10(3), depending on wavelength
.