This project investigates a new concept of a multi-functional fiber optic sensor platform in the field of fiber optic sensors and sensor systems. The primary research goal is to investigate, develop, and achieve a conceptually new multi-functional fiber optic sensor system to demonstrate the new concept, which will be achieved by using the newly developed fiber loop ringdown (FLRD) technique. FLRD measures a single variable, time, to detect any quantity of interest, e.g., pressure, temperature, strain, concentration of a chemical species, etc. This universal time domain sensing scheme offers the potential of multiplexing multiple FLRD sensor units into a single sensor system to simultaneously sense multiple quantities with high sensitivity, high speed of detection, and minimal adverse impacts from intensity fluctuations of the light source.
Specific research objectives include: 1) Design, fabricate, and evaluate each individual FLRD sensor unit for the detection of different measurands. 2) Design, develop, and fabricate a multi-functional fiber sensor system. 3) Develop and optimize data processing algorithms. 4) Demonstrate and evaluate performance of the sensor system in terms of functionality, network capability, data transmission and processing efficiency, and capability of maintaining high performance (sensitivity, accuracy, selectivity, and robustness of each individual sensor unit and the speed of the whole sensor system). This project will involve one graduate student and one undergraduate student from Applied Engineering Physics.
This project is a study of a new concept of a multi-functional fiber optic sensor platform in the field of fiber optic sensors and sensor systems. Fiber loop ringdown (FLRD) is relatively new to sensing communities; its potential for development of new generation sensor systems remains little explored. The research activities proposed in this project have achieved a suite of new FLRD sensors and demonstrated a new type of sensor network using a uniform sensing signal—time. The research activities helped advance the field of sensing science and technology beyond the single function and single location sensing constrained by the conventional sensing schemes to the simultaneous multi-function, high-performance, and multi-location sensing using the new time-domain FLRD sensing scheme. This multi-functional fiber optic sensor platform is practically impossible to be achieved by using the conventional sensing schemes. The innovation of the sensor platform is three-fold: 1) A single sensor platform enables multiple sensor units to be added to simultaneously sense multiple quantities in a single time domain, 2) Each sensor unit has ringdown-enhanced high sensitivity and high speed of detection, and 3) The novel sensor platform enables the maximum number of sensor units to be multiplexed into a sensor system without adverse impacts from power fluctuations and power losses of the light source. Social benefits are primarily in the area of sensors and sensing systems. For example, in civil engineering (dams, bridges, pipelines, etc.), novel sensors with multi-sensing functions are needed to monitor loading history and mechanical fatigue, detect early leakage, access post-storm damage, and identify toxic industrial chemicals in a remote and timely manner. In the US coal-fired power plants, a multi-functional sensor system is needed for operation control and monitoring. In the US old nuclear facilities, multi-function, low maintenance cost, and long life-time sensor network is needed for long-term remote monitoring. The new FLRD sensing technique also has great application potential in subsea engineering. The new sensor platform will generate significant impacts on potential cost reductions in future sensor design, deployment, and operation. This project has trained five graduate students, three undergraduate students, and one high school student. The research activities have been exposed to more than 80 science/engineering students and 200 high school students from local high schools. Nine peer-reviewed journal articles, five conference proceedings, ten conference presentations, and one book chapter, which are direct results from this project, effectively disseminate the research findings and scientific data to sensor and sensing communities.
