Laser Self-Mixing Sensor for Simultaneous Measurement of Young’s Modulus and Internal Friction

Abstract

The Young’s modulus and internal friction are two important parameters of materials. Self-mixing interferometry (SMI) is an emerging non-destructive sensing method that has been employed for various applications because of its advantages of simple structure, ease of alignment and high resolution. Some recent works have proposed the use of SMI technology to measure the Young’s moduli and/or internal frictions by measuring the resonance frequencies and damping factors of specimen vibrations induced by impulse excitation. However, the measurement results may be affected by frequencies of SMI fringes, and the implementation requires extra signal processing on SMI fringes. In this work, we developed an all-fiber SMI system without SMI fringes to measure the Young’s modulus and internal friction simultaneously. Simulations and experiments were carried out to verify the feasibility of the proposed method. Two specimens of brass and aluminum were tested. The experimental results show that the standard deviations of Young’s moduli for brass and aluminum are 0.20 GPa and 0.14 GPa, and the standard deviations of internal frictions are 4.0×10−5 and 5.4×10−5, respectively. This method eliminates the influences of the SMI fringe frequency on the resonant frequency and requires no signal processing on SMI fringes, contributing to its simplicity as a method for the measurement of the Young’s modulus and internal friction.

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

“…However, the sensitivity must still be improved [ is an emerging nondestructive sensing technology and is often used to measure physical parameters such as distance, displacement and velocity [13][14][15][16]. When th nal conditions lead the change of the phase of the feedback light, the output light i of the laser will exhibit interference fringes similar to the Michelson interference such a structure is often called self-mixing interferometer [17][18][19][20]. In a self-mixin ferometer, the mixing interference takes place inside the laser internal cavity.…”

Enhanced Vibration Measurement through Frequency Modulated Laser Diode Self-Mixing Interferometry

“…The SMI concept was successfully validated, as the measurements were statistically equivalent between the two methods. Recent works have proposed using SMI as a promising non-destructive sensing method employed for measuring the Young's moduli and internal frictions by detecting the resonance frequencies and damping factors of specimen vibrations induced by impulse excitation [25].…”

High precision estimation of optical feedback factor and linewidth enhancement using non-dominated sequential genetic algorithm II (NSGA-II)

“…Self-mixing interferometry (SMI) [1], a promising non-destructive sensing technique, has achieved a wide range of applications in recent years for measurement and sensing applications in experimental and practical engineering environments due to the advantages of its compact system structure, low implementation cost, and easy optical alignment. These applications involve a wide range of fields such as displacement, vibration, absolute distance [2], velocity, mechanical and material metrology [3], biomedical sensing, etc. The SMI technique specifically involves the outer surface reflection or backscattering of the laser beam emitted from a laser at the surface of an external object, which is then reinjected into the laser cavity via the original optical path and mixed with the original laser field.…”