Cylinder manufacturing methods can influence specification, offering recommendations on what to consider when designing cylindrical optical components to minimize cost and allow for greater flexibility in manufacturing.
There are parameters used in specifying centration of a lense and techniques used to check the location of and position the optical axis. Whether centering errors are specified in terms of decenter or wedge, it all comes back to the difference in edge thickness.
One design strategy for an optical system is centering two or more lenses together to build a lens assembly. However, strain in excess may cause delamination or fracture of the assembly elements, so it is important to consider the management of it.
Selecting the material from which a lens is made is a fundamental design consideration. In certain situations, a substitute or equivalent material may need to be identified depending on the specifications.
There are two main paths for tolerancing spherical radii: power tolerance and linear radius tolerance. Both measure change relative to a nominal value, but the metrology used is the key difference.
Mechanical attribute tolerances can be a major cost driver because of time and yield penalties added to fabrication of a lens. Dimensions and their tolerances are interrelated, so designers need to balance function and budget.
Centration errors arise from deviation from superposition. In a perfectly centered lens, the mechanical and optical axes are concurrent and coincidental, superimposed on each other.
Phase-shifting interferometry is widely used to determine form errors of an optical surface in optical manufacturing. These distortions can affect the ability to get accurate data on thin film coated optical surfaces.