Optofluidics for dynamically programmable illumination

Abstract: An ideal illumination system should be able to adapt optimally to the needs of the user. Such dynamically programmable illumination systems open up extraordinary possibilities, ranging from tunable intensity distributions and dynamic lighting scenarios to information transmission, and would improve the functionality for a wide range of applications. To achieve this functionality, tunable light sources that can respond dynamically to control signals are required. This thesis describes the development of an optofluidic system that allows the generation of dynamically programmable intensity distributions.The developed system utilizes the electrowetting-on-dielectrics (EWOD) mechanism to define variable optical surfaces using a liquid/liquid interface as a dynamic optical element that can be adjusted by 16 individually addressable electrodes. The interface enables the generation of arbitrary intensity distributions by modulating a two-dimensional phase shift. However, this functionality is only possible if the phase shift generated by the interface can be accurately determined and reconstructed. Therefore, two phase retrieval algorithms based on neural networks and least-squares optimization are presented in this thesis. In addition, three methods are presented that can be used to precisely reconstruct arbitrary surface profiles with the liquid/liquid interface. The working principle of the developed phase retrieval and surface reconstruction algorithms is demonstrated by experimentally reconstructing arbitrary surface profiles with the developed optofluidic system, which are then used to generate desired intensity distributions. Finally, this approach is used to demonstrate the capability of a two-dimensional phase-shifter array to generate larger, more complex, dynamically programmable intensity patterns

Object Details

• Location: Deutsche Nationalbibliothek Frankfurt am Main
• Extent: Online-Ressource
• Language: Englisch
• Notes: Universität Freiburg, Dissertation, 2024

Classification and Topics

• Classification: Elektrotechnik, Elektronik

Contributors, Places and Time

• Event: Veröffentlichung
• (where): Freiburg
• (who): Universität
• (when): 2025
• Creator: Sieben, Merit
• Contributor: Zappe, Hans P. ; Wallrabe, Ulrike ; Albert-Ludwigs-Universität Freiburg. Fakultät für Angewandte Wissenschaften

Further information

• DOI: 10.6094/UNIFR/263200
• URN: urn:nbn:de:bsz:25-freidok-2632003
• Rights: Open Access; Der Zugriff auf das Objekt ist unbeschränkt möglich.
• Last update: 15.08.2025, 7:36 AM CEST