ECE Research Seminar Series
Join the ECE Department as we host a seminar with guest speaker, Dr. Shaolin "Allen" Liao. Dr. Liao will present his talk, "Kilometers-long Fiber Laser Sensors & Array with Graphene."
ABSTRACT
Kilometers-long sensing of physical and chemical parameters with ultra-high sensitivity has been enabled by the emerging miniature feedback modulated fiber laser sensors and their arrays. Due to its sensitivity, kilometers-long remote measurement capability, simple detection method and ease of array multiplexing, the feedback modulated fiber laser sensor has many important applications such as self-driving automobile Lidar, Non-destructive Evaluation (NDE) of materials & structures, Structure Health Monitoring (SHM) of infrastructures like distributed temperature of smart grid power line, and sensing of distance, displacement, vibration, velocity, thin film/coating thickness, materials refractive index, thermal expansion, liquid level and acoustics. This talk will first cover the fundamental principle of the fiber laser sensors based on the feedback modulation physics phenomenon. Then, optimal design of the fiber laser sensor at 1550 nm wavelength within the optical communication C-band is achieved through the first-principle simulation with in-house Python codes. The simulation is self-consistent because it solves the laser power coupled nonlinear rate equations of the fiber laser gain medium iteratively. Also, the efficient coupled modes theory method is used to accelerate the laser wave propagation simulation. The Python numerical simulation can obtain all sensing parameters like lasing power, lasing efficiency, saturation power, and sensitivity. Then a 1-km Fiber Laser Microphone (FLM) prototype has been optimally designed and built with a graphene diaphragm as the feedback modulating sensing element. Experiment has been carried out and shows that the 1-km long FLM can detect acoustic signal up to 10 kHz. What’s more important, the experimental results confirms the optimal design very well. At last, a two-element array of FLMs has been assembled to demonstrate the feasibility of the sensor array for imaging application.
BIOGRAPHY
Dr. Shaolin “Allen” Liao obtained his Ph.D. degree in Electrical and Computer Engineering (ECE), 1st Master Degree in Materials Science Program, and 2nd Master Degree in ECE, in 2003, 2005, and 2008 respectively, all from the University of Wisconsin, Madison, USA. Dr. Liao obtained his B.S. degree in Materials Science & Engineering, from Tsinghua University in 2000. Dr. Liao performed his 1st Post-doc at Physics at the City University of New York (CUNY: 2008-2010) and 2nd Post-doc at Nuclear Engineering at Argonne National Laboratory (ANL: 2010-2013). He became a R&D Scientist at ANL since 2013 and at the same time an Adjunct Faculty (Research Professor & Part-time Teacher) at the Illinois Institute of Technology (IIT: 2017-present). Dr. Liao’s research interests are highly diversified with focus on applied electromagnetics & photonics, and Computational Electromagnetics (CEM). He has published >70 journal/conference papers with IEEE, OSA, SPIE and APS. Dr. Liao is an Associate Editor of IEEE Access and an IEEE Senior Member.
If you have any questions about the seminar, please contact the ECE department (312.567.3400 or ece@iit.edu)