Optical properties of ion beam modified waveguide materials doped with erbium and silver

In the first part of this thesis we investigate codoping of erbium-doped waveguide materials with different ions in order to increase the efficiency of erbium-doped optical amplifiers. Codoping with ytterbium can overcome the limitations due to the small absorption cross section of Er3+ in Al2O3 at 980nm. Yb3+ absorbs radiation of that wavelength efficiently and transfers energy to Er3+. In Al2O3 we have measured energy transfer rates of up to 2500s-1. However, in designing erbium/ytterbium codoped amplifiers care has to be taken to optimise the Yb3+ concentration, since its large absorption cross section strongly depletes the 980nm pump in a waveguide. Codoping with europium or cerium increases the transition rate between the second and first excited state of Er3+ in Y2O3. This provides a higher population in the first excited state of erbium in optical amplifiers pumped at 980nm. Due to the specific energy level structure of the ions, the increase of the transition rate is twice as large for europium codoping than for cerium codoping. Codoping Er-doped glass with silver ions largely increases the excitation probability of erbium when excited in the ultraviolet and visible. The excitation spectrum shows that the pump absorption takes place at Ag-related centres. From there the energy is transferred to Er3+. The second part of this thesis is devoted to the study of metallodielectric composites consisting of silver nanocrystals in glass. These composites are fabricated by ion implantation of inert gas ions into Na+?Ag+ ion-exchanged glass. We demonstrate two applications of the optical properties of these materials: (a) integration of the silver nanocrystals in optical waveguides provides long wavelength pass filters, whose cut-off depends on the length of the region containing Ag nanocrystals. (b) The strong variation of the index of refraction of the metallodielectric in the visible region can be used for the formation of diffraction gratings, written directly into the glass by ion irradiation through a suitable mask. We demonstrate diffraction on a sample irradiated through a self-assembled mask of colloidal silica particles

Reliability of polymer electronics on plastic film

Different working groups have already shown the possibilities of organic electronics for realization of low cost electronic circuits. In the mean time different technology demonstrators have been presented by different groups ranging from transistor level to ring oscillators or even digital circuits. However a crucial issue for polymer electronic applications is their reliability. Most prominent reliability limitation is the sensitivity on humidity as the most prominent reason for degradation. But also mechanical stresses, which are only minor relevant to silicon electronics due to the rigidity of the silicon wafers, they play a major role for polymer electronics on flexible substrates. At IZM we investigated the behaviour of polymer electronic circuits under different stress conditions. The devices have been fabricated on metallised PET film, where the basic source-drain electrodes are fabricated by a reel-to-reel photolithography process. Two coating steps are performed to process the active layer with polymer semiconductor of the PTAA type and a gate dielectric. Finally three screen printing steps are used to finish the polymer electronic process. A more detailed description of the fabrication process is given in ref. 1 and 2. Stable transistor function has been reached under normal ambient conditions with on-currents in the µA- and off-currents in the nA-range

Elektrisch funktionales Mehrschichtfoliensystem und Verfahren zum Herstellen desselben

DE 102009015742 A1 UPAB: 20101101 NOVELTY - The system (100) has a foil substrate (102) with a contact area (104) and an electrical functional element (106) connected with the contact area. An intermediate foil (120) is arranged between the foil substrate and another foil substrate (110). An electrically conductive material (124) is arranged in a passage hole (122-1) of the structured intermediate foil to make an electrically conductive connection between the contact area of the former foil substrate and a contact area (112) of the latter foil substrate. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for a method for manufacturing an electrically functional multi-layer foil system. USE - Electrically functional multi-layer foil system. ADVANTAGE - The foil system is designed such that electronic components e.g. silicon chips and displays, are integrated and associated with one another for enabling outer variable integratability of different electrical functional elements within the electrical functional multi-layer foil system in a simple manner

Technologies for functional hetero-system integration on foil

2-conductor Flex for R2R Organic Electronics in R2R Thin Chip Integration for R2R Micro-Systems in R2R - Smart Plastic

A novel point of care diagnostic device: Impedimetric detection of a biomarker in whole blood

There is an unmet medical need for a more reliable and earlier assessment of patients suspected of having a deep vein thrombosis. We describe a novel approach which is developing a highly reliable, accurate, portable and handheld prototype medical diagnostic device to improve radically the speed, accuracy and reliability with which DVT and related blood clotting conditions can be assessed. The device will measure whole blood concentration of D-dimer, a recognized biomarker of increased blood clotting activity, and through innovation in the development of a novel detection, measurement and reporting system, will offer the opportunity to use the test in the point of care setting. The device combines innovation in antibody bio-engineering for high specificity immunoassay-based diagnostics and nano/micro engineered impedimetric analysis electrodes incorporating a biocompatible polymer substrate with development of a disposable microfluidic manifold specifically enabling diagnostics at the point-of-first-contact. © 2007 IEEE