摘要
阐述了一种平面薄板结构的平面型光纤Bragg光栅(Fiber Bragg Grating,缩写为FBG)水听器探头的工作原理,从理论和实验上分析研究了该探头的结构灵敏度、频率响应特性以及加速度响应特性。平面圆形薄板采用不锈钢,尺寸为:直径15 mm、厚度0．15 mm,探头为圆柱型,尺寸为:直径17 mm、长20 mm。对于该尺寸结构的FBG水听器,探头静态灵敏度可达23 fm/Pa,比裸光栅增敏7300倍;谐振频率为6．5 kHz,而且幅频特性在100 Hz～5．5 kHz频率范围内较为平坦;低频段加速度响应灵敏度为:58～75(fm·s^2/m),在1 m/s^2加速度作用下其输出等效(2．52～3．26 Pa)压力作用下的输出。该结构的探头也便于多路复用组成水听器阵列。该平面结构不仅可以组成光纤FBG水听器探头,同样可以组成光纤光栅激光水听器探头。对薄板的几何尺寸进行适当的调整,可实现不同量程、不同带宽的水声压力测量。
This paper puts forward the planar Fiber Bragg Grating （FBG） hydrophone probe sensing principle, theoretically and experimentally researches the probe structure sensitivity, the receiving sensitivity frequency response characteristic and the acceleration response property. Planar circle sheet is made of stainless steel, its thickness is 0.15 mm, its diameter is 15 mm, and the length of hollow circular shell is 20 mm. For this size of the structure, the probe structure sensitivity is up to 23 fm/Pa, which is about 7300 times of the value of the bare fiber. The resonance frequency is 6.5 kHz, and the amplitude-frequency curve of the receiving sensitivity response is relatively flat within the frequency range of 100 Hz-5.5 kHz. The output yielded by one unit acceleration（1 m/s^2） is equivalent to （2.52-3.26 Pa） acoustic pressure acting output. This probe structure is easy to form FBG hydrophone array by multiplexing technique. Research shows that this planar structure not only can form FBG probe, but also can constitute optical FBG laser probe. The structure can realize different bandwidth, different range acoustic pressure measurement by adjusting the geometrical size of the sheet.
出处
《声学学报》
EI
CSCD
北大核心
2007年第4期343-348,共6页
Acta Acustica
基金
武汉市青年科技晨光计划资助项目(20065004116-20)
