SBIR Phase I: Photonic Crystal-Based Optical Fiber Temperature Sensors for Process Control

This Small Business Innovation Research Phase I project aims to develop novel photonic crystal-based optical fiber sensors for the rapid measurement of temperature for real-time process control and civil structure monitoring applications. A patented molecular-level electrostatic self-assembly (ESA) processing method will be used to form multi-layered dielectric stacks with periodically interleaved high and low refractive indices on the distal ends of optical fibers to achieve one-dimensional photonic crystal sensor structures. Such dimensionally-resonant optical structures can be used in several configurations to measure temperature change by detecting thermally-induced resonance mode frequency shifts. Both the temperature measurement range and resolution of such physically small and mechanically robust sensors can be controlled by varying packaging material constitutive properties. Similar devices suggests a typical dynamic range of 80C, resolution of 0.2C and response time of microseconds, orders of magnitude faster than conventional contact-based thermal probes. During Phase I a major research university would assist through thin film materials analysis and optical device testing. There is an immediate need for such fast response time temperature sensors in a commercialized and field-deployed instrumentation system for the oil and gas industry. Fast response time temperature sensors have specific applications in closed-loop feedback control systems. Similar photonic crystal-based sensors may be applied to measurements of strain, pressure and chemical and biological targets.