Laser Self-Mixing Interference: Optical Fiber Coil Sensors for Acoustic Emission Detection

Acoustic emission (AE) testing is a widely used nondestructive testing method for the early detection of failures in materials and structures. In this paper, an AE detection sensor combining optical fiber sensing with laser self-mixing interference (SMI) technology is proposed. A multi-coil optical fiber ring wound round a cylindrical acrylic skeleton was designed in order to sense the deformation caused by AE elastic waves, which was then demodulated using self-mixing interference technology. Finite element analyses were conducted in order to investigate the deformation of fiber under acoustic sources. AE signals induced via ball-dropping impact experiments were successfully detected by the proposed experimental system. The proposed SMI optical fiber AE sensing system has the advantages of being free from electromagnetic interference and having a simple structure, low implementation cost and high measurement resolution and sensitivity.

Automated summary

This paper proposes an acoustic emission (AE) detection sensor that combines optical fiber sensing with laser self-mixing interference (SMI) technology. It can detect failures in materials and structures at an early stage. Through finite element analysis and experimental verification, the proposed system has been shown to have advantages such as resistance to interference, simple structure, and high measurement accuracy and sensitivity.