NICOP - Simulation of Pulsing Effect in Fiber Laser Dynamic Behaviour caused by Scattering Losses generated by Acoustic Waves
Abstract
Structural Health Monitoring (SHM) provides a diagnosis of the ~state~ of a structure in terms of thematerials, the different parts"", and the full assembly of these parts that constitute the structure as awhole. Acoustic emission (AE) detection is a common method"" for SHM, measured using piezoelectricbasedsensors which are made of solid ceramic, and thus the contact point between the structur"es andsensor is small limiting the sensitivity especially for large or long structures. Large number of sensors isrequired for large or long structures making the usage impractical.Fiber laser dynamics behaviour is present when the laser is operating slightly above the lasing thresholdwhere the optical cavity starts to produce stimulated emission but in an unstable condition. Whenacoustic" wave is exerted on the fiber cavity, it causes scattering losses on the electromagnetic wavestravelling in the fiber. These losses" will suppress the stimulated emission generation thus allowingpopulation inversion to build-up that leads to large pulsing effect. The laser dynamics behaviour basedacoustic sensor makes use of the sensitivity of the fiber laser system to the surrounding acoustic wavesto monitor acoustic activity around the fiber cavity.The objectives of the project are:1) To develop a theoretical model in understanding the principle of fiber laser dynamics2) To simulate the laser dynamics behaviour when fiber laser is modulated by acoustic waves3) To validate simulated results with measurement data and provide detailed analysis of laserdynamics behavior unde"r external acoustic wave perturbationWith the model and simulation, it is expected that a better understanding of laser dynamics un"deracoustic wave perturbation can be achieved and utilizing the knowledge to develop a highly sensitivefiber laser based AE sensor. The research output can be used especially by aircraft operators fordamage detection solutions to reduce the maintenance costs and fleet downtime.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Dec 20, 2017
- Source ID
- N629091812014
Entities
People
- Faidz Abd Rahman
Organizations
- Office of Naval Research
- United States Navy
- Universiti Tunku Abdul Rahman