Leiden University Student Repository

Fagginger Auer, Fedde (2017)

Wavefront sensing with liquid crystal focal plane phase masks

Bachelor thesis | Natuurkunde (BSc)

Direct imaging of exoplanets is an extremely difficult task limited by distortions caused by both the atmosphere and telescope optics. Current extreme adaptive optics systems (XAO) can correct these distortions, but require precise wavefront measurements. The Zernike wavefront sensor was developed to do this. The new vector-Zernike wavefront sensor (vZWFS), built using liquid crystal technology, is a promising improvement over the old Zernike wavefront sensor. In this thesis we test a vZWFS prototype and compare its response with the results of a model written in Python. In the experiment we introduce phase aberrations through a spatial light modulator, which are then measured by the vZWFS. We model part of the physical setup and use it to interpret the physical measurements. We create a method to reconstruct the phase and amplitude of the original wavefront, and test the limitations of the vZWFS.

adaptive optics

zernike

phase contrast

geometric phase

liquid crystal

wavefront sensing

Author

Fagginger Auer, Fedde

Faculty

Faculty of Science

Supervisors

Snik, Frans

ECTS Credits

3

Language

en