The London Geotechnical Centrifuge Centre at City University London

The London Geotechnical Centrifuge Centre located at City University, London is one of four currently active centrifuges in the UK. The centrifuge is well used and much of the geotechnical research at City University employs physical modelling but supported by a large element testing facility and numerical modelling capability. The centre was...

De Saint-Venant equations-based model assessment in model predictive control of open channel flow

Model selection for salt water intrusion in delta areas

Due to land subsidence and sea level rise, salt intrusion in delta areas increases. This is a potential thread for agriculture in these areas. To investigate this thread and measures that can counteract on it, numerical models are developed to mimic the behavior of the water system under different strategies and scenarios. This behavior is...

Master of Science

Photoanisotropic polarization gratings beyond the small recording angle regime

Polarization gratings can be realized by polarization holographic recording in photoanisotropic materials. In this paper, we study two types of polarization gratings. One is recorded with two orthogonally circularly (OC) polarized beams and the other one with two orthogonally linearly (OL) polarized beams. The interference of both cases is...

Applicability of geometrical optics to in-plane liquid-crystal configurations

We study the applicability of geometrical optics to inhomogeneous dielectric nongyrotropic optically anisotropic media typically found in in-plane liquid-crystal configurations with refractive indices no=1.5 and ne=1.7. To this end, we compare the results of advanced ray- and wave-optics simulations of the propagation of an incident plane wave...

Diffractive Optics of Anisotropic Polarization Gratings

Diffraction gratings are being used to manipulate light in many different applications, such as in flat panel display systems, modern lighting systems, and optical recording. Diffraction gratings can be made polarization selective due to form birefringence. An alternative approach to polarization selective gratings is to use birefringent...

Characterization of the diffraction efficiency of polymer-liquid-crystal-polymer-slices gratings at all incidence angles

Recently, a novel holographic diffraction grating made of polymer slices alternated to homogeneous films of nematic liquid crystal (POLICRYPS) was realized. We study the optical performance of the POLICRYPS gratings by both numerical simulations and experiments. Characterization of the grating at normal and conical reading mount are performed....

Simulations of birefringent gratings as polarizing color separator in backlight for flat-panel displays

A color and polarization separating backlight can be obtained by using a surface-relief grating made of birefringent material as an outcoupling structure on top of the lightguide. A rigorous finite element diffraction model was applied to study the polarization effect of such a grating. The diffraction of plane waves by the anisotropic grating...

Birefringent gratings to be used as polarized colour-separator for liquid crystal displays

Poster presentation Optics Research Group TU Delft in cooperation with Philips and STW

The integral equation approach to kinematic dynamo theory and its application to dynamo experiments in cylindrical geometry

The conventional magnetic induction equation that governs hydromagnetic dynamo action is transformed to an equivalent integral equation system. An advantage of this approach is that the computational domain is restricted to the region occupied by the electrically conducting fluid and to its boundary. This integral equation approach is applied to...

Wire-grid diffraction gratings used as polarizing beam splitter for visible light and applied in liquid crystal on silicon

The application of wire grid polarizers as efficient polarizing beam splitters for visible light is studied. The large differences between the transmissivity for different polarizations are explained qualitatively by using the theory of metallic wave guides. The results of rigorous calculations obtained by using the finite element method are...