Modal wavefront correctors based on nematic liquid crystals

Modal wavefront correctors are active optical components for the compensation of aberrated optical wavefronts in a smooth and continuous way. They are traditionally represented by membrane and continuous faceplate deformable mirrors. This thesis is dedicated to the investigation and development of modal wavefront correctors based on nematic...

Data-Driven Optimal Control for Adaptive Optics

Adaptive optics (AO) is a technique to actively correct the wavefront distortions introduced in a light beam as it propagates through a turbulent medium. Nowadays, it is commonly applied in ground-based telescopes to counteract the devastating effect of atmospheric turbulence. This thesis focuses on the control aspects of AO. Whereas most AO...

Model-based Control in Adaptive Optics Systems

Adaptive optics (AO), also called as Smart Optics, has received increasing attention in the past decades. The main idea behind AO is to actively sense and compensate the optical aberration in the system such that the image resolution is improved or the light beam is well focused. The applications of AO include ground-based telescopes, scanning...

Adaptive mirror micromachined in silicon

Adaptive Optics to Counteract Thermal Aberrations: System Design for EUV-Lithography with Sub-nm Precision

In highly precise systems the thermal expansion of system-parts is of increasing concern, since it can severely compromise its performance at sub-nanometre level. An example of such a system is an Extreme UltraViolet (EUV)-lithography machine that is used in the semi-conductor industry to project the pattern of the chip onto a silicon wafer. In...

CMOS-based Integrated Wavefront Sensor

This thesis addresses the design, implementation and performance of an integrated Hartmann-Shack wavefront sensor suitable for real-time operation and compatible with a standard technology. A wavefront sensor can be used for the detection of distortions in the profile of a light beam or of an optical component.With such a sensor, one can, for...

Adaptive Optics for EUV Lithography: Phase Retrieval for Wavefront Metrology

In the semiconductor industry, optical lithography is presently the most widespread technology used to print a geometrical pattern on a semiconductor wafer. Because of the plans imposed by the International Technology Roadmap for Semiconductors (ITRS) for more powerful and smaller chips, new printing technologies capable of printing smaller...

Adaptive deformable mirror dynamics and modular control

The refractive index of air varies a.o. with temperature, humidity, pressure and the CO2 concentration. Due to atmospheric turbulence this refractive index varies both in space and in time, leading to aberrations in images of light having passed though it. These aberrations limit the achievable resolution of optical telescopes such that the...

Adaptive optics: A liquid formable mirror for high-order wavefront correction

Abstract not available

Optical tools towards the improvement of optogenetic stimulation

Optogenetics is a powerful addition to the spectrum of techniques available in neuroscience to investigate neurophysiology and unravel how neural circuit structure is related to circuit function. This technique relies on introducing lightsensitive proteins or molecules as actuators to transduce an optical signal into a physiological perturbation...

Physical and Computational Approaches to Aberration Correction In Fluorescence Microscopy

The goal of this thesis, called Physical and Computational Approaches to Aberration Correction In Fluorescence Microscopy, concerns itself with the development of new techniques to control adaptive fluorescence microscopes, so that they can adapt and image with increased resolution, contrast and speed inside complex three-dimensional biological...

Spline-based wavefront reconstruction for Shack-Hartmann measurements

In the coming decade, a new generation of extremely large-scale ground-based astronomical telescopes will see first light. It is well known that increasing the size of the telescope aperture is only beneficial if the adaptive optics (AO) system, which compensates for turbulence-induced wavefront aberrations, scales accordingly. For the extreme...