Indium tin oxide overlayered waveguides for sensor applications

The use of indium tin oxide (ITO) thin films as electrodes for integrated optical electrochemical sensor devices is discussed. The effect of various thicknesses of ITO overlayers exhibiting low resistivity and high transparency on potassium ion-exchanged waveguides fabricated in glass substrates is investigated over the wavelength range 500-900 nm. ITO overlayers are formed by reactive thermal evaporation in oxygen, followed by annealing in air to a maximum temperature of 320°C. With air as superstrate, losses in the waveguides were found to increase dramatically above 30nm ITO thickness for TE polarization, and above 50nm thickness for TM. Losses were increased over the whole wavelength range for a superstrate index close to that of water. A one-dimensional multilayer waveguide model is used in the interpretation of the experimental results

The Wicker Tube Reactor – Characterization and Modeling

A new type of reactor for continuous emulsion polymerization was characterized by measurements of the residence time distribution in water and during a chemical reaction. These measurements show nearly plug flow behavior even in the laminar flow region. The thermal behavior was modeled with respect to temperature, monomer and initiator concentration. Continuous emulsion polymerization can be run inherently safe and with remarkable high space time yield in the new wicker tube reactor