When designing a lens system, the optical designer typically seeks to minimize the overall cost to meet a given set of specifications. The designer must consider not only the nominal design performance, but also the effects of fabrication tolerances, alignment errors and compensation methods that have an impact on the final “as-built” performance. Systems requiring tight tolerances or complicated compensation strategies in order to meet the performance specifications will generally be more expensive to manufacture and more complicated to assemble. Ideally, the designer will produce a design form that meets as-built performance goals and is naturally less sensitive to fabrication and alignment errors.
There are a number of published methods for desensitizing a lens as part of the optimization process. Many of these methods apply optimization constraints that indirectly control system sensitivity. The indirect approaches can be effective, but do not directly correlate to typical performance specifications (such as RMS wavefront error).
Continue reading-Novus Light Today
