Integrated optical polarizer based on the cross strip interferometer configuration.

A bimodal segment of specific length and thickness between two single mode sections of a planar waveguide can serve as a simple interferometer. The configuration can be realized by etching a wide strip from a dielectric film and forcing a — vertically guided, laterally unguided — beam of light to traverse the strip perpendicularly. A TE-pass polarizer designed on the basis of this concept achieves more that 30dB polarization discrimination with a total length of only 5 micrometers, for air covered Silicon-Oxide/Nitride waveguides at a wavelength of 650 nanometers

The earths gravity field to 16th degree and station coordinates from satellite and terrestrial data

Geodetic parameters of earth gravity field and satellite tracking station positions in geocentric reference fram

A spiral-shaped mach-zehnder interferometric sensor for monitoring thickness changes in bioreceptor layers

Design issues of a spiral-shaped Mach-Zehnder interferometer are discussed

Silicon oxynitride in integrated optics

A review on the state of the art of silicon oxynitride deposition at the MESA Research Institute will be given. The recent progress in the application of silicon oxynitride in communication devices will be discusse

Nanomechanical optical devices fabricated with aligned wafer bonding

This paper reports on a new method for making some types of integrated optical nanomechanical devices. Intensity modulators as well as phase modulators were fabricated using several silicon micromachining techniques, including chemical mechanical polishing and aligned wafer bonding. This new method enables batch fabrication of the nanomechanical optical devices, and enhances their performance

Integrated optics sensors for multi-sensing platforms

An overview is presented of research projects on optical sensing, in the Integrated Optical MicroSystems group of the MESA+ Institute for Nanotechnology at the University of Twente

SEA LEVEL CHANGE ALONG THE TYRRHENIAN COAST FROM EARLY HOLOCENE TO THE PRESENT

In any discussion of the evolution of a river basin, the history of sealevel change is important since river gradients and delta developments are strongly influenced by local sea level. Also, sea level provides a reference for inferring past vertical tectonic stability from the geological record. Hence it is appropriate that the discussion on the Tiber basin starts with sea level change along the Tyrrhenian coast during the Holocene. The past evidence for sea level comes from inferences of the position of the sea surface with respect to the present. Hence it is a relative measure; a function of both the changing position of the ocean surface and of the land surface or an integrated measure of changes in ocean volume, land movement and redistribution of water within the ocean basins. The observation therefore contains information on all the processes that change these surfaces: on geophysical, glaciological and oceanographic processes

Laser interference lithography with highly accurate interferometric alignment

It is shown experimentally that in laser interference lithography, by using a reference grating, respective grating layers can be positioned with high relative accuracy. A 0.001 degree angular and a few nanometers lateral resolution have been demonstrated

Laser interference lithography with highly accurate interferometric alignment

Three dimensional photonic crystals, e.g. for obtaining the so-called woodpile structure, can, among others, be fabricated by vertical stacking of multiple gratings. One of the requirements for obtaining a full photonic bandgap in such a photonic crystal is an accurate angular and lateral alignment of the successive gratings. Using laser interference lithography at 266 nm wavelength, we fabricated gratings in silicon with periods down to 300 nm. We present a method for aligning further grating exposures with respect to this grating with a 0.001 degree angular and a few nanometers lateral resolution