A Fibre Bragg Grating Acoustic Emission and Transmission Sensor Utilizing a Transmit Reflect Detection System
Faculty of Computing, Health and Science
School of Engineering
We present a Transmit Reflect Detection System (TRDS) for a Fibre Bragg Grating (FBG) acoustic emissions and transmissions sensor. The TRDS utilises both the transmitted and reflected signals of a narrow band laser source, from a FBG. The transmitted and reflected signals are edge filter detected, via two separate photoreceivers. The received transmitted and reflected signals are then differentially amplified, increasing the total received signal. The TRDS improves the sensitivity and efficiency of the FBG acoustic emission and transmission sensor. The TRDS also has greater thermal stability over conventional FBG edge filter detection systems. The TRDS and FBG sensor was used to successfully receive actively generated ultrasonic signals, including acousto-optic communications signals, and to detect acoustic emissions. We present results of the frequency and the transient response of the FBG sensor, and the acoustic emissions for low energy drop tests, and a lead pencil break test.