Dynamic optical wavefront synthesizer- design, fabrication and systems integration (Wavesynth)

• Applicant: Professor Dr. Stefan Sinzinger
• Subject Area: Measurement Systems
• Term: from 2017 to 2024
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 390737909

The project `wavesynth` is focused on the dynamic generation of quasi arbitrary wavefronts, i.e. a wavefront synthesizer. In order to enable powerful applications we develop efficient approaches to model, design and integrate optical modules with tunable functionality into functional systems. By shifting or rotating freeform optical elements within the beam path it is possible to adjust the wavefronts within an optical system or in its exit pupil quasi arbitrarily to a specific functionality. This approach, which has been discussed already for many years (Alvarez-Lohmann Linsen), allows for tuning dynamics and aperture sizes which can be adapted to the requirements of the optical system in an optimum way. In combination with the high reproducibility which can be achieved with the appropriate positioning units this represents the biggest potential advantages over alternate approaches for tunable optical performance such as tunable microfluidic lenses. Systematic modelling of the investigated wavefront synthesizers is an essential foundation for the successful systems integration. To this end we derive analytical models which allow one to take the dynamic optical properties into consideration already during the search for appropriate start systems. Adapted models allow for the integration of corresponding cost functions in the design process as well as the analysis of system tolerances to imperfections of the alignment and fabrication of the freeform elements. For demonstrating the functionality of the tunable optical modules we choose the realization as diffractive optical elements. Besides the occurring losses in light efficiency which also have to be taken into account, the diffractive implementation offers potential for new enhanced functionalities. Optical modules or systems with tunable optical functionalities offer unique potential for innovative applications in areas such as imaging, metrology or sensing. Additional new areas of applications are possible, e.g. in so called `computational Imaging` in combination with numerical methods for image processing or wavefield propagation. In a demonstration experiment we will use our tunable optical wavefront synthesizers for optimization of phase retrieval from intensity measurements. This will be interesting also for wavefront sensing or imaging with synthetic aperture.

• DFG Programme: Research Grants