SBIR Phase I: Optical Detectors Based on Transparent Microwires and Nanowires on Plastic Film

This Small Business Innovation Research (SBIR) Phase I project will develop a new type of optical power monitor based on microwires and nanowires patterned within a transparent multi-layer anti-reflection coating. These wires are nanometer to micron wide traces patterned within an indium tin oxide (ITO) conductive layer. ITO typically absorbs 1 to 10% at visible and infrared wavelengths, depending on its thickness. Localized heating of ITO occurs when the optical intensity passing through the conductive trace exceeds about 1 mW/mm2. The temperature change produces a proportional resistance change that can be measured electronically. This detector samples and transmits light with nearly zero insertion loss. By incorporating this patterned ITO coating within traditional antireflection coatings and thin film interference coatings, novel detection schemes can be developed. Moreover, by reducing the dimensions of the trace to the nanometer scale, the detector also has the potential for high-speed operation with a bandwidth approaching GHz. The broader impacts/commercial potential of this project will be a detection technology that enables a wide range of new optical monitoring applications by eliminating costly and bulky assemblies. For instance, inexpensive and miniature optical monitors can potentially replace the ten million passive fiber optic connector adapters produced annually for fiber optic communication systems. By transparently measuring the optical power through fiber optic junctions in a low cost fashion, advanced self-monitoring and self-diagnosing communication network architectures can be realized for Fiber-to-the-Home and data centers. This technology promises to reduce the cost to measure power within optical fibers by two orders of magnitude. These detectors have the potential to be mass-produced on flexible plastic film, window glass, mirrors, or even on curved substrates such as light bulbs and lenses. This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).