【摘要】 提出了一种新颖的基于四芯光纤的弯曲传感器,可用于弯曲测量。该传感器采用一段四芯光纤作为敏感单元,四芯光纤的四个纤芯作为一个四光束干涉仪,在光纤出射端远场形成周期分布的干涉格子。该四光束干涉仪的干涉相位差是光纤弯曲曲率半径的函数,因而,弯曲曲率半径的变化可导致格子光场的移动。波长为650 nm的低相干半导体激光二级管被用来做为光源,所形成的干涉格子光场由CCD探测器记录。理论上,建立了远场格子图案强度分布函数与曲率半径的关系,并得到了实验的验证。更多还原

【Abstract】 A novel four-core fiber-based bending sensor has been proposed,in which four-core fiber is used as the sensing element,the four cores of the fiber act as a four-beam interferometer,and the far-field interferogram grids with periodical distributions are formed on the fiber output end.The phase difference is a function of the radius of curvature,so the change of the radius of curvature shifts the far-field interferometric grid pattern.A low-coherence laser diode with wavelength of 650 nm is adopted to illuminate the fiber and the interferogram pattern in the far-field is recorded by a CCD camera.The relationship between the far-field grid pattern intensity distribution and the radius of curvature is established theoretically and confirmed experimentally.更多还原