Sub-wavelength metrology using Coherent Fourier Scatterometry

Scattering is the process in which some form of radiation is deviated from its trajectory by a localized non-uniformity it encounters. These non-uniformities, called objects, can be of different material and geometry which determines among many things, mainly, the amount and direction of the scattered radiation. Scatterometry is the branch of...

Coherent fourier scatterometry

The electronics which makes our lives easier like mobiles, computers, digital cameras contain chips with very small semiconductor components like transistors. When transistors can be made even smaller, the chip can accommodate a larger number of components, which gives more processing capacity, resulting in a faster device with an increased...

Silicon photonic micro-ring resonators to sense strain and ultrasound

We demonstrated that photonic micro-ring resonators can be used in micro-machined ultrasound microphones. This might cause a breakthrough in array transducers for ultrasonography; first because optical multiplexing allows array interrogation via one optical fiber and second because the silicon-on-insulator technology allows cost-effective...

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...

On super resolved spots in the near-field regime

When dealing with optics, the increasing level of understanding of a given problem relies on a good description of the behavior of the light in that optical system. In general, a numerical model should be devised, based on experimental evidences, in order to account for the specific problem under study. Approximations, such as ignoring...

Rigorous simulations of emitting and non-emitting nano-optical structures

In the next decade, several applications of nanotechnology will change our lives. LED lighting is about to replace the common light bulb. The main advantages are its energy efficiency and long lifetime. LEDs can be much more efficient, when part of the emitted light that is currently trapped in the device, could be radiated out of the device....

The Extended Nijboer-Zernike Diffraction Theory and its Applications

In present-day society, we encounter optical systems on a daily basis. Most people have a DVD player capable of playing content stored on an optical disc, Big Brother is watching us nearly everywhere using surveillance cameras and we consider it to be normal to take photographs with our mobile phone. Also, in less visible areas, such as...

Ray-optics analysis of inhomogeneous optically anisotropic media

When the optical behavior of light in a medium depends on the direction in which light is traveling, the medium is called optically anisotropic. Light is an electromagnetic wave and in this thesis, we discuss the electromagnetic theory on optical anisotropy. We do this with the assumption that the wavelength of light approaches zero. The field...

A systematic analysis of the optical merit function landscape: Towards improved optimization methods in optical design

A major problem in optical system design is that the optical merit function landscape is usually very complicated, especially for complex design problems where many minima are present. Finding good new local minima is then a difficult task. We show however that a certain degree of order is present in the optical design space, which is best...

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...

An analytic approach to electromagnetic scattering problems

Mark formation model for optical rewritable recording

Optically rewritable discs contain one or more so-called recording stacks. These stacks consist of various grooved layers. At least one of these layers contains a so-called phase-change material. In the recording layer, amorphous regions are formed on a crystalline background by means of high power laser pulses. During read-out, differences in...

Three dimensional rigorous model for optical scattering problems

We present a three-dimensional model based on the finite element method for solving the time-harmonic Maxwell equation in optics. It applies to isotropic or anisotropic dielectrics and metals, and to many configurations such as an isolated scatterer in a multilayer, bi-gratings and crystals. We shall discuss the applications of the model to high...