Grant: Research Tools and Instruments - Category 1 (<$150,000)

A fast sweeping laser and detection system is requested to support initially two current research programs of highly significance for the development of sensing technology: Program 1: Distributed acoustic and vibration sensors (Dr. Bao and Dr. Colin Rennie): Building on existing polarization measurements achieved so far through this collaborative program, the requested system will add distributed functionality to the system by detecting phase of the backscattered Rayleigh signal to get position information for acoustic waves as crack detection and vibration spectrum for currents. Program 2:  Testing of the coherent distributed sensor for water currents and crack detection (Dr. Bao, Dr. Rennie): This program addresses two crucial issues: a) The replacement of the existing point sensor with the distributed acoustic and vibration sensor based on this fast weeping laser and fast detection system, so that turbulent velocity profiles can be detected. By measuring the mean and fluctuations of these known currents we can have better understanding of ocean circulation and predict the consequence of global warming effect. b) The higher vibration frequency at distributed fashion allows detection and quantifies structural deterioration and damage in global picture, rather than at discrete point, which is not adequate to predict the status of the structure. To extend service life and higher performance of infrastructures, it is important to have early detection of the cracks through distributed acoustic wave measurement, and study its implication to the bridges and overpasses for disaster prevention. Without the requested equipment, these research programs would be considerably limited and the urgent contributions to the development of sensing technology practically impossible to achieve.