Polarimetric heterodyning fiber laser sensor for directional acoustic signal measurement.
A DBR fiber grating laser acoustic sensor based on polarization beat signal modulation analysis has been demonstrated for directional acoustic signal measurement. The acoustic sensor was fabricated in birefringent erbium-doped fiber, and the influences of external-acoustic pressure on fiber grating laser sensor were analyzed, considering the effect of relative orientation of the acoustic wave on the degrees of birefringence modulation. In experiment, the birefringence in sensing fiber was modulated by ultrasonic pressure. Agreement between theoretical and experimental results was obtained for ultrasound wave propagating from different directions (0-360 degrees in 15 degrees intervals) corresponding to a nonlinearly change in beat frequency modulation rates. The results demonstrate that the DBR fiber grating laser acoustic sensor has an orientation recognizable ability, offering a potential for acoustic vector signal detection.
School of Electronic Information Engineering,Tianjin University,Tianjin 300072, China. lvchengang@tju.edu.cn
Chengang
C
Lyu
Chuang
C
Wu
Hwa-Yaw
HY
Tam
Chao
C
Lu
Jianguo
J
Ma
D000162:Acoustics / Q000295:instrumentation*; D017076:Computer-Aided Design; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005336:Fiber Optic Technology / Q000295:instrumentation*; D007834:Lasers; D012031:Refractometry / Q000295:instrumentation*; D013016:Sound; D020349:Surface Plasmon Resonance / Q000295:instrumentation*; D014159:Transducers