Proposed the ring cavity all fiber F-P interferometer used in AE (acoustic emission) detection. By welding the incidence and the exit of the 2×2 optical fiber coupler directly

structure the optical fiber ring cavity

it can be attached or embed in the measured solid to detect the AE signals. Determined the detection property of the optical fiber sensor through the theoretical derivation and the simulation of computer. PZT (Piezoelectric Ceramic) is powered by signal generator as the continuous known ultrasonic source

and the blast wave that is adopted to simulate the burst AE signal in marble slab

they were used to be detected by the optical fiber sensor

and then the characteristic frequency of acoustic emission signal is obtained by Fourier technique. The experimental results indicate that the system can detect acoustic emission signals that cause the optical fiber stretching to 10-8m in axial direction and identify the characteristic frequency of it

this optical fiber sensor works without the match of optical path and apply to monitor the large scale component. It provides a new method for the health examination and the monitoring for material structure.