Background: An optical waveguide is a structure that guides electromagnetic waves in the optical spectrum. Optical waveguides commonly are used to support and illuminate photocatalysts; for example they could be used in remediating effluent waste streams by photocatalytic oxidation or photooxidation. Transition metal oxides such as titanium dioxide are effective photocatalysts. However metal oxide-based photocatalytic processes typically involve a low ratio of illuminated catalyst surface area to reactor volume the photocatalyst must be fixed in the reactor to separate from the reactant and the photocatalyst does not use the activating ultraviolet radiation efficiently. A photocatalytic system that efficiently propagates UV light in a coated photocatalytic waveguide is needed. Such a waveguide would allow for the controlled interaction of light energy with a large photocatalyst surface area thus enhancing the efficiency of heterogeneous photocatalytic processes. Improved waveguides also could be the basis for novel optical chemical and biochemical sensors. Technology Description: UW–Madison researchers have developed a waveguide that propagates light in an attenuated total reflection (ATR) mode i.e. it enables samples to be examined directly in the solid liquid or gas state without further preparation. The device comprises a transparent internal reflection element (IRE) and a porous particulate transition metal oxide coating on at least one surface of the IRE. This device potentially could be useful for the economical scale-up of photocatalytic reactors for commercial remediation applications. Applications: Optical waveguides Patent Status: US6285816 Opportunity for collaboration: The Wisconsin Alumni Research Foundation (WARF) is seeking commercial partners interested in developing an optical waveguide that requires fewer light sources and provides for improved efficiency in various applications.
1) Requires fewer light sources reducing the cost of UV light generation 2) Evenly distributes the activated catalyst throughout the reactor volume 3) Efficiently captures diffuse light such as sunlight or light from a fluorescent lamp for photocatalysis biological or chemical sensing or increasing the efficiency of a photovoltaic cell 4) Smaller light intensity gradient than conventional photoreactors that are activated by direct illumination
US6285816 Opportunity for collaboration: The Wisconsin Alumni Research Foundation (WARF) is seeking commercial partners interested in developing an optical waveguide that requires fewer light sources and provides for improved efficiency in various applications. (http://pimg-fpiw.uspto.gov/fdd/16/858/062/0.pdf)