title: Highly flexible MTF measurement system for tunable micro lenses.
abstract: We present an efficient, low-cost modulation transfer function (MTF) measurement approach, optimized for characterization of tunable micro-lenses; the MTF may easily be measured at a variety of different focal lengths. The approach uses a conventional optical microscope with an optimized approach for lens illumination and the measurement results have been correlated with a commercial MTF measurement system. Measurements on fixed-focus and tunable micro-lenses were performed; for the latter, resolution for lenses with back focal length of 11 mm was 55 lines/mm, decreasing to 40 lines/mm for a back focal length of 4 mm. In general, it was seen that performance was better for lenses with longer focal lengths.
authors.affiliation: Laboratory for Micro-optics, Department of Microsystems Engineering - IMTEK, University of Freiburg, Georges-Koehler-Allee 102, 79110 Freiburg, Germany. wei.zhang@imtek.uni-freiburg.de
authors.forename: Wei
authors.initials: W
authors.lastname: Zhang
authors.forename: Khaled
authors.initials: K
authors.lastname: Aljasem
authors.forename: Hans
authors.initials: H
authors.lastname: Zappe
authors.forename: Andreas
authors.initials: A
authors.lastname: Seifert