The most frequently used lens-to-mount interfaces involve direct contact of shaped shoulders, spacers and/or retainers onto the polished lens surfaces or onto ground bevels. In some cases, the lens rim may contact a machined surface of the mount. Elastomeric suspension of the lens in the mount is a possible alternative design. Surfacecontact mount types reviewed here include "sharp corner", tangent and toroidal interface versions using retaining rings to hold the lenses against shoulders or spacers. Means for conservatively estimating stress build-up with-in the lens due to axial preload at assembly and at extreme temperatures are suggested. Examples showing the influences of different material characteristics (such as coefficients of thermal expansion and Young's modulus) and of both positive and negative changes of temperature from that existing at assembly are discussed.
Paul R. Yoder, Paul R. Yoder,
"Advanced considerations of the lens-to-mount interface", Proc. SPIE 10265, Optomechanical Design: A Critical Review, 102650E (28 December 1992); doi: 10.1117/12.61111; https://doi.org/10.1117/12.61111