2020

• Strauch, M: Tunable Optics: Spectral Imaging and Surface Manipulation on Liquid Lenses. Delft University of Technology, Delft, 2020
  

  @PhdThesis{Strauch2020,
    author      = {Strauch, M},
    title       = {Tunable Optics: Spectral Imaging and Surface Manipulation on Liquid Lenses},
    institution = {Delft University of Technology},
    year        = {2020},
    date        = {2020-03-30},
    type        = {phdthesis},
    subtitle    = {Spectral Imaging and Surface Manipulation on Liquid Lenses},
    language    = {English},
    isbn        = {978-94-028-1994-6},
    pagetotal   = {151},
    doi         = {10.4233/uuid:b61aa64e-cba4-44c0-8d16-93440e028611},
    
    abstract    = {This thesis focusses on two aspects of tunable optics: Fabry-P{\'e}rot interferometers with a variable distance between their mirrors and electrowetting liquid lenses. The need for a device to detect child abuse has motivated us to design and build a camera that can detect the chemical composition of the upper skin layers of a bruise using a self-made Fabry-P{\'e}rot interferometer. The research described in the first part of this thesis has shown that wide-angle spectral imaging can be achieved with compact and cost-effective cameras using Fabry-P{\'e}rot interferometers. Designs with a full field of 90° in which the Fabry-P{\'e}rot interferometer is mounted either in front of an imaging system or behind a telecentric lens system are presented and analysed. The dependency of the spectral resolution on the numerical aperture of the lens system is derived and its value as a design criterion is shown. It is shown that the telecentric camera design is preferable over the collimated design for bruise imaging with a Fabry-P{\'e}rot interferometer.The idea to use a liquid lens for spectral imaging has directed the research towards a new concept of controlling surface waves on the surface of a liquid lens. We investigate and model surface waves because they decrease the imaging quality during fast focal switching. We propose a model that describes the surface modes appearing on a liquid lens and that predicts the resonance frequencies. The effects of those surface modes on a laser beam are simulated using geometrical optics and Fresnel propagation, and the model is verified experimentally. The model of the surface oscillations is used to develop a technique to create aspheric surface shapes on commercially available electrowetting liquid lenses. The surface waves on the liquid lens are described by Bessel functions of which a linear combination can be used to create any circularly symmetrical aspheric lens shape at an instant of time. With these surface profiles, one can realise a large set of circularly symmetrical wavefronts and hence intensity distributions of beams transmitted by the lens. The necessary liquid lens actuation to achieve a desired shape is calculated via a Hankel transform and confirmed experimentally. The voltage signal can be repeated at video rate. Measurements taken with a Mach-Zehnder interferometer confirm the model of the surface waves. The capabilities and limitations of the proposed method are demonstrated using the examples of a Bessel surface, spherical aberration, an axicon, and a top hat structure.},
  keywords = {AG-Huber},
    address     = {Delft},
    publisher   = {Delft University of Technology},
    school      = {Delft University of Technology},
  }

2019

• Weng, D; Hakert, H; Blömker, T; Kolb, JP; Strauch, M; Eibl, M; Lamminger, P; Karpf, S and Huber, R: Sub-Nanosecond Pulsed Fiber Laser for 532nm Two-Photon Excitation Fluorescence (TPEF) Microscopy of UV transitions. 2019 Conference on Lasers and Electro-Optics Europe and European Quantum Electronics Conference, in 2019 Conference on Lasers and Electro-Optics Europe and European Quantum Electronics Conference, pp. ch_9_3, Optical Society of America, 2019
  

  @inproceedings{Weng:19,
  author = {Weng, D; Hakert, H; Bl\"{o}mker, T; Kolb, JP; Strauch, M; Eibl, M; Lamminger, P; Karpf, S and Huber, R},
  booktitle = {2019 Conference on Lasers and Electro-Optics Europe and European Quantum Electronics Conference},
  journal = {2019 Conference on Lasers and Electro-Optics Europe and European Quantum Electronics Conference},
  keywords = {Fiber lasers; Fluorescence lifetime imaging; Frequency doubled lasers; Laser sources; Live cell imaging; Master oscillator power amplifiers},
  pages = {ch_9_3},
  publisher = {Optical Society of America},
  title = {Sub-Nanosecond Pulsed Fiber Laser for 532nm Two-Photon Excitation Fluorescence (TPEF) Microscopy of UV transitions},
  year = {2019},
  keywords = {AG-Huber_NL},
  doi = { 10.1109/CLEOE-EQEC.2019.8872571},
  abstract = {Two-photon microscopy is a powerful technique for in vivo imaging, due to its high penetration depth and axial sectioning. Usually excitation wavelengths in the near infrared are used. However, most fluorescence techniques for live cell imaging require labeling with exogenous fluorophores. It has been shown that shorter wavelengths can be used to excite the autofluorescence of endogenous proteins, e.g. tryptophan \[1\].},
  }
  

2018

• Strauch, M;Somers, P A. A. M.;Bociort, F and Urbach, H. P: Creation of aspheric interfaces on an electrowetting liquid lens using surface oscillations. AIP Advances 8(11), 2018
  

  @article{Strauch2018,
     author = {Strauch, M;Somers, P A. A. M.;Bociort, F and Urbach, H. P},
     title = {Creation of aspheric interfaces on an electrowetting liquid lens using surface oscillations},
     journal = {AIP Advances} {8(11)},
     
     ISSN = {2158-3226},
     DOI = {10.1063/1.5063994},
     year = {2018},
     type = {Journal Article}
  }
  

2017

• Strauch, M;Konijnenberg, S;Shao, Y and Urbach, H P: Wavefront shaping with an electrowetting liquid lens using surface harmonics (Conference Presentation). no. 10073, SPIE, 2017
  

  @book{Strauch2017-3,
     author = {Strauch, M;Konijnenberg, S;Shao, Y and Urbach, H P},
     title = {Wavefront shaping with an electrowetting liquid lens using surface harmonics (Conference Presentation)},
     publisher = {SPIE},
     volume = {10073},
     series = {SPIE BiOS},
     url = {https://doi.org/10.1117/12.2252854},
     year = { 2017 },
     type = {Book}
  }
  

• Strauch, M;Shao, Y;Bociort, F and Urbach, H. P: Study of surface modes on a vibrating electrowetting liquid lens. Applied physics Letters111 (17), pp. 171106, 2017
  

  @article{Strauch2017,
     author = {Strauch, M;Shao, Y;Bociort, F and Urbach, H. P},
     title = {Study of surface modes on a vibrating electrowetting liquid lens},
  journal = {Applied physics Letters}{111 (17)},
  
    
     pages = {171106},
     DOI = {10.1063/1.4999562},
  keywords = {lenses,surface waves(fluid),vibrations,wetting},
  abstract = {The increased usage of liquid lenses motivates us to investigate surface waves on the liquid's surface. During fast focal switching, the surface waves decrease the imaging quality. We propose a model that describes the surface modes appearing on a liquid lens and predicts the resonance frequencies. The effects of those surface modes on a laser beam are simulated using Fresnel propagation, and the model is verified experimentally.
  We acknowledge the use of an educational licence of CODE V and LightTools. This work was funded through the Spectr@phone project (IPD 12017) of the IOP Photonic Devices program of RVO.},
  
     url = {https://aip.scitation.org/doi/abs/10.1063/1.4999562},
     year = {2017},
     type = {Journal Article}
  

2016

• Strauch, M and Urbach, H P: Surface harmonics on liquid lenses. in 2016 IEEE Photonics Conference (IPC), pp. 248-249, Oct, 2016
  

  @INPROCEEDINGS{Strauch2017,
  author={Strauch, M and Urbach, H P},
  booktitle={2016 IEEE Photonics Conference (IPC)},
  title={Surface harmonics on liquid lenses},
  year={2016},
  
  pages={248-249},
  keywords={lenses;optical harmonic generation;optical tuning;oscillations;surface harmonics;liquid lenses;tunability;nonspherical surfaces;surface oscillations;Lenses;Liquids;Surface waves;Optical surface waves;Harmonic analysis;Shape;Optical switches},
  doi={10.1109/IPCon.2016.7831063},
  ISSN={},
  month={Oct},}

2015

• Strauch, M;Livshits, I L;Bociort, F and Urbach, H P: Wide-angle spectral imaging using a Fabry-Pérot interferometer. no. 10, 2015
  

  @book{Strauch2015,
     author = {Strauch, M;Livshits, I L;Bociort, F and Urbach, H P},
     title = {Wide-angle spectral imaging using a Fabry-Pérot interferometer},
     volume = {10},
     series = {2015},
     ISBN = {1990-2573|escape}},
     url = {https://www.jeos.org/index.php/jeos_rp/article/view/15037%J Journal of the European Optical Society - Rapid publications},
     year = {2015},
     type = {Book}
  }