SBIR Phase II: Optical Detectors Based on Transparent Microwires and Nanowires

This Small Business Innovation Research (SBIR) Phase II project will develop a new type of optical power monitor utilizing transparent microwires and nanowires patterned within a multi-layer anti-reflection coating. These "wires" are nanometer to micron wide traces defined within a transparent indium tin oxide (ITO) conductive layer. ITO typically absorbs 1 to 10% at visible and infrared wavelengths, depending on its thickness, and optical intensities greater than 1 mW/mm2 produce measureable localized heating. This temperature change induces a proportional resistance change that can be measured electronically. By inserting this detector in-line between fiber optic cables, the optical power of the internal signals can be measured without degrading the signal strength. 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 impact/commercial potential of this project includes new optical monitoring applications that were previously impossible or impractical. In one example, inexpensive and miniature optical monitors can now be integrated within the hundreds of millions of fiber optic interconnects produced annually for fiber optic communication systems. Advanced self-monitoring and self-diagnosing communication network architectures can be developed for Fiber-to-the-Home networks and data centers by transparently measuring the optical power through fiber optic junctions. This technology promises to reduce the cost to measure power within optical fibers by two orders of magnitude, and has the potential to be mass-produced and even inkjet printed on flexible plastic film, window glass, solar panels, mirrors, displays, or even on curved substrates such as light bulbs and lenses.