2.5D etching of silicon dioxide for optical and photonic structures. - In: IEEE Xplore digital library, ISSN 2473-2001, (2022), insges. 2 S.
We investigated the ability to control the sidewall-angle for the etching of SiO2 by tuning process parameters. We found a strong correlation between sidewall-angle and temperature, enabling control of the sidewall-angle from 60˚-90˚, and found a curved etch profile which was named quasi-isotropic.
Manufacturing of nanostructures in silicon carbide using UV-nanoimprint lithography in combination with fluorine-based plasma etching. - In: IEEE Xplore digital library, ISSN 2473-2001, (2022), insges. 2 S.
The combination of a multi-layer resist system for soft UV-NIL with a fluorine-based plasma etching is investigated to elaborate homogeneously distributed nanosized features in silicon carbide. Initial studies substantiate that this approach can be a timesaving and cost-effective alternative to generate nanostructures in SiC.
Simulation model and dimensioning of a photoacoustic sensor for the detection of radiation-induced pressure surges. - In: MikroSystemTechnik, (2021), S. 523-526
Whispering Gallery Resonators with diffractive coupling elements. - In: MikroSystemTechnik, (2021), S. 230-233
Vergleich zur Plasmastrukturierbarkeit von Materialien mit sehr geringer thermischer Ausdehnung. - In: MikroSystemTechnik, (2021), S. 51-54
Efficient and cost-effective manufacturing of nanostructures with high aspect ratios using Soft UV-Nanoimprint Lithography with bi- and trilayer resist systems. - In: MikroSystemTechnik, (2021), S. 35-38
Traceable 5D-nanofabrication with nano positioning and nano measuring machines. - In: Proceedings of the 21st International Conference of the European Society for Precision Engineering and Nanotechnology, (2021), S. 333-336
Today, besides the ongoing progress in the reduction of feature sizes, the measuring and fabrication of freeform surfaces with nanometre uncertainty, e.g. for aspheric lenses or structures with high aspect ratios, are a challenging task. Usually, dealing with such objects is limited by the local tilt angle between the object surface and the tool axis. There are different approaches to perform such measurements. In this paper, an extension of the Nano Measuring Machine NMM-1 with two rotational axes is described. With the proposed setup, it is possible to orientate the tool-axis perpendicular to the sample in every position, allowing larger angles to be measured / structured and minimising the uncertainty of the process e.g. due to the tilt dependency of the tool. Various machine designs are investigated and finally a solution with one rotary and one goniometer stage is integrated, preserving the existing machine infrastructure and allowing the addressability of a full hemisphere without limiting the measuring volume. As the tool centre point maintains its position during tool rotation, the Abbe principle is still fulfilled in every angular orientation. Emphasis was put on the metrological traceability of the whole system, including linear and rotary axes as well the tool itself. This was achieved by using a reference hemisphere, compensating the trajectory errors of the rotational axes. For the developed arrangement, the measurement uncertainty was investigated and several strategies for an in-situ-calibration of the additional axes are described. Finally, nanofabrication on large slopes is demonstrated.
Deformed microcavities with very high Q-factors and directional farfield emission. - In: EOS Annual Meeting (EOSAM 2020), (2020), 01006, S. 1-2
We report the design and optimized fabrication of deformed whispering gallery mode resonators in silica with solely ICP-RIE. This allows us to control the morphology of the resonators more freely and results in low surface roughness. The light was coupled into the resonator using a state of the art tapered fiber approach and we determined the Q-factor in the range of 10^5
Optische Systeme im Phasenraumbild. - In: DGaO-Proceedings, ISSN 1614-8436, Bd. 121 (2020), B29, insges. 2 S.
Compressive sensing hyperspectral imaging with optimized diffractive optical elements. - In: Photonic Instrumentation Engineering VII, (2020), insges. 1 S.
Hyperspectral image acquisition is challenging due to its three-dimensional dataset consisting of two spatial and one spectral dimensions. Available spectral imagers are either based on spatial or spectral scanning or they sacrifice spatial and spectral resolution for snapshot imaging. Compressive Sensing techniques have already been applied to spectral imaging to enhance the image acquisition, but they still rely on multiple consecutive measurements. We utilize several diffraction orders of a novel diffractive optical element whose diffraction efficiency has been optimized for a broad wavelength range. Based on this diffractive optical element we design and compare novel compressive snapshot spectral imaging systems and present experimental results.