The KArlsruhe TRItium Neutrino experiment (KATRIN) aims to measure the absolute neutrino mass scale with an unprecedented sensitivity of 0.2 eV/c 2 (90% C.L.), using β decay electrons from tritium decay. The kinetic energy of the decay electrons is measured using an electrostatic integrating main spectrometer with magnetic adiabatic collimation and requires a certain magnetic field profile. For the control of the magnetic field in the main spectrometer area two networks of mobile magnetic field sensor units are developed and commissioned. The radial system is operated close to the outer surface of the main spectrometer whereas the vertical one is mounted along vertical planes left and right of the main spectrometer. The sensor setup can take several thousand magnetic field samples at a fine meshed grid, thus allowing to study the magnetic field inside the main spectrometer and the influence of magnetic materials in the vicinity of the main spectrometer.

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Micro-opto-electro-mechanical systems (MOEMS) micromirror and shutter arrays have gained huge interest in research and applications. Our study starts with an overview on the technological achievements and experimental results of groups that have been working on this field. The main part of our study is revealing the MOEMS micromirror array technology for light steering via smart glazing for buildings. The mirror array is actuated electrostatically and integrated between the panes of insulation glazing. Depending on user activity as well as daytime and season requirements, the MOEMS micromirror arrays shall enable personalized light steering, energy saving, and reduction of CO 2 emission. Technological fabrication of subfield addressing up to 64 fields inside the arrays is presented. Experimental characterization results such as actuation voltages, maximum and minimum transmission, contrast, and energy saving potential are reported. Using an industrial window module fabrication process, a laboratory demonstrator and a function demonstrator have been implemented. Rapid aging tests including vibrations, extreme temperatures, multiple temperature cycles, and long-term electrostatic actuation of micromirror structure were performed to evaluate reliability and lifetime. These results validate extrapolated lifetimes-in future applications as active windows-far beyond 40 years, as well as their robustness during transportation, installation, and against all vibration influences in buildings. © The Authors. Published by SPIE under a Creative Commons Attribution 4.0 Unported License. Distribution or reproduction of this work in whole or in part requires full attribution of the original publication, including its DOI.

Fabry-Pérot (FP) filter arrays fabricated by highresolution three dimensional (3D) NanoImprint technology are presented. A fabrication process to implement 3D templates with very high vertical resolution is developed. Filter arrays with 64 different cavity heights have been fabricated requiring only one single imprint step. Different optical methods are involved in this paper to characterize geometric and spectral properties. In order to investigate the transfer accuracy of the surface quality from the NanoImprint template to the filter, we use white light interferometry (WLI) measurements. Surface roughness and structure height accuracy of <1 nm for both values demonstrate the conservation of these critical parameters during the 3D NanoImprint process. Additionally, an optical characterization methodology for spectral transmission and reflection measurements of the filter arrays is introduced and applied. A compact microscope spectrometer setup which allows efficient handling, high resolution and short inspection time is verified by comparing measurement results to that of an optical bench setup used as a reference. First, this paper focuses on the foundation of the FP filter arrays, second on the technological fabrication, third on validation calibration of the setup and forth on the characterization of the filter arrays. The measurements envisage the spectral position of filter transmission lines, the full width at half maximum (FWHM) and the

Optical measurement techniques are widely applied in high-resolution contour, topography and roughness measurement. In this context vertical scanning white-light interferometers and confocal microscopes have become mature instruments over the last decades. The accuracy of measurement results is highly related not only to the type and physical properties of the measuring instruments, but also to the measurement object itself. This contribution focuses on measurement effects occurring at edges and height steps using white-light interferometers of different numerical apertures. If the edge is perfectly perpendicular, batwing effects appear at height steps. These batwings show maximum height if the height-to-wavelength-ratio (HWR) is about one forth or three forth, and they disappear if the HWR value is about an integer multiple of one half. The wavelength that is relevant in this context is the effective wavelength, i.e. the center wavelength of the illuminating light multiplied by a correction factor known as the numerical aperture correction. However, in practice the edges are usually not perfectly perpendicular. In this case, the measurement results depend also on the derivative of the surface height function and they may differ from theory and the prediction according to the HWR value. Measurements of such steps show systematical effects depending on the lateral resolution of the instrument. In this context, a Linnik interferometer with a magnification of 100x and NA = 0.9 is used to characterize the three dimensional topography of more or less rectangular calibration specimens and quasi-perpendicular structures produced by the nanoimprint technology. The Linnik interferometer is equipped with LED light sources emitting at different wavelengths, so that the HWR value can be changed. This is possible since the high NA objective lenses show a rather limited depth of focus such that the temporal coherence gating may be replaced by focal gating in this particular instrument. In addition, measurement results are compared with those achieved by a Mirau interferometer of NA = 0.55. A commercial confocal microscope with NA of 0.95 serves as a reference instrument for further comparison. Numerical simulations considering diffraction effects are carried out in order to explain the experimental results obtained by the different white and colored light interferometers.