Fiber Bragg grating (FBG) strain sensor has plastic segmented sheath that is coated on Bragg grating of optical fiber, whose length, outer diameter and inner diameter are set to specific range

摘要

The FBG strain sensor has optical fiber (1) having outer diameter (d) of 0.01-0.9 mm. A Bragg grating (2) having length (l) of l-20 mm is coated with a plastic segmented sheath (3) whose length (Ll) is 3-50 mm, outer diameter (D1) is 0.2-1.9 mm and inner diameter (D2) is 0.1-1.3 mm. The ratio of length of segmented sheet and length of Bragg grating is set to 0.7-9, the ratio of outer diameter of segmented sheath and outer diameter of optical fiber is set to 1.3-110, and ratio of inner diameter of segmented sheath and outer diameter of optical fiber is set to 1.01-2.