Measurement devices with and for micro-optics at the University of Erlangen

Several devices for the measurement of micro-optical elements will be presented. These are a Mach-Zehnder interference microscope for the measurement of the wave aberrations of microlenses in transmission using a HeNe laser (633 nm wavelength) and a shearing interferometer for the measurement of microlenses in transmission in the near infrared (1319 nm). This shearing interferometer uses two Ronchi gratings to provide a lateral shear and is therefore very compact and stable. We also describe a Twyman-Green interference microscope for the measurement of (nearly) spherical surfaces in reflection using partially coherent illumination. Microlenses can be also used to build measurement devices from micro- and macro-optics. We will present a Shack-Hartmann wavefront sensor with microlenses for the measurement of quite arbitrary wavefronts and a confocal set-up which uses an array of microlenses and stops to provide a confocal measurement without a lateral scanning of the object. This confocal set-up can be used to measure the surface profile of micro-optical structures like gratings or microlenses.