Optical inspection and characterization of microoptics using confocal microscopy

With the growing demand for microoptics in different areas the importance of the characterization increases. Methods for a fast defect detection in microlens arrays are developed. We present a technique where the confocal principle is applied for determining the variation and the absolute value of the focal length. Additionally, using a self-filtering method the deviation of the periodic structure of microlens arrays is investigated theoretically and experimentally. Point-like defects as well as aberrations have been detected. The introduced methods allow the fast, parallel characterization of microlens arrays.