Licht-donker, 0-1, zwart-wit

Estimating resist parameters in optical lithography using the extended Nijboer-Zernike theory

Optimizing Fourier filtering for digital holographic particle image velocimetry

Finding new local minima by switching merit functions in optical system optimization

Comparison of blind imaging performance of Fizeau and Michelson type arrays for a partially resolved object

This paper compares two well-known types of interferometer arrays for optical aperture synthesis. An analytical model for both types describes the expected output, in terms of photon counts. The goal is to characterize the performance of both types of array for blind imaging of a wide-field or extended object that would be partially resolved by...

A deformable mirror based on electrocapillary actuation of a liquid surface

We propose and demonstrate a novel liquid based deformable mirror (LDM). The proposed LDM consists of an array of vertically oriented open capillary channels immersed in a pool of two immiscible liquids. A free-floating thin reflective membrane serves as the reflecting surface. By means of jet action, membrane deformation is induced. The control...

Correction of the phase retardation caused by intrinsic birefringence in deep UV lithography

In the year 2001 it was reported that the birefringence induced by spatial dispersion (BISD), sometimes also called intrinsic birefringence, had been measured and calculated for fluorides CaF2 and BaF2 in the deep UV range. It was also shown that the magnitude of the BISD in these cubic crystals is sufficiently large to cause serious problems...

Demonstration of nulling using delay line phase shifters

We present results of experiments obtained using a new nulling technique that enables deep nulling without the use of achromatic phase shifters. The experimental set-up consists of a three-beam interferometer that should provide a nulling depth of several thousands over a wavelength range of 500 to 650 nm. The intended depth of null was not...

Experimental performance of homothetic mapping for wide field interferometric imaging

Homothetic mapping is an aperture synthesis technique that allows interferometric imaging over a wide fieldof-view. A laboratory experiment was set up to demonstrate the feasibility of this technique. Here, we present the first static experiments on homothetic mapping that have been done on the Delft Testbed for Interferometry (DTI). Before a...

Avoiding unstable regions in the design space of EUV mirror systems comprising high-order aspheric surfaces

When Extreme Ultraviolet mirror systems having several high-order aspheric surfaces are optimized, the configurations often enter into highly unstable regions of the parameter space. Small changes of system parameters lead then to large changes in ray paths, and therefore optimization algorithms crash because certain sssumptions upon which they...

Determination of resist parameters using the extended Nijboer-Zernike theory

This study presents an experimental method to determine the resist parameters that are at the origin of a general blurring of the projected aerial image. The resist model includes the effects of diffusion in the horizontal plane and a second cause for image blur that originates from a stochastic variation of the focus parameter. The used...

The effect of intrinsic birefringence in deep UV-lithography

The subject of birefringence induced by spatial dispersion (BISD), also called intrinsic birefringence, recently became an important issue for 157-nm lithography. For the deep UV range, because of intrinsic absorption, only crystalline materials can be used as optical materials for lens manufacturing. The physical properties of crystals are...

Optimisation of polishing processes by using iTIRM for in-situ monitoring of surface quality

The possibilities of iTIRM, an in-process surface measurement tool, are explored in this research. Experiments are done to test the applicability for qualifying and optimising finishing processes for optical surfaces. Several optical glasses, different polishing agents and ductile grinding are included in these experiments. It is concluded that...

Beantwoording van vragen betreffende de airlift

Baggerwerktuig voor slikvelden en ondiepe sloten. (4de-jaars opdracht)

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