Centration Analysis of Cylindrical Lenses: From Single Elements to Multilens Systems

Cylindrical lenses are increasingly vital in LIDAR systems, microlithography, and cinema optics. Unlike spherical surfaces defined by a single tilt parameter, a cylinder is geometrically described by its axis or apex line, requiring a three-dimensional metrological approach.

This presentation gives a framework to characterize three critical quantities for singlets: lateral decentering (offset), clocking (azimuth angle), and wedge error. These are measured using an electronic autocollimator by observing focal and afocal section planes to isolate specific surface errors. Experimental results demonstrate sub-micron accuracy for decenter and high angular accuracy for wedge and azimuth errors.

Furthermore, Langehanenberg details "MultiLens" methodology for the non-destructive characterization of fully assembled anamorphic systems. By treating cylindrical surfaces as dual-design elements and iteratively analyzing both X-Z and Y-Z intersections, the centering state of every internal surface can be determined. Validation confirms calculations match direct surface measurements with high precision. Langehanenberg concludes with how existing spherical metrology tools can be successfully adapted for high-precision cylindrical optics with minor hardware adjustments.

About the presenter
Patrik Langehanenberg, Ph.D., obtained his doctorate degree for his work in the field of low coherence digital holographic microscopy from the University of Muenster, Germany in 2009. Since then, he has been with TRIOPTICS GmbH in various R&D and product management roles. Currently, he serves as a technical liaison between sales, product management, and research for optomechanical metrology solutions (OMS). In this role, he focuses on identifying emerging technology trends and innovation potentials, while driving the alignment of technical concepts with market needs.