1results about How to "Increased strain sensitivity" patented technology

This invention discloses an FBG strain sensor based on misaligned fusion spliced ​​coreless optical fiber and its fabrication method. The sensor comprises an input single-mode fiber, multiple segments of coreless optical fiber, and an output single-mode fiber connected sequentially. The input single-mode fiber is fused together with the first segment of the coreless fiber in a misaligned manner, and the next segment of the coreless fiber is fused together with the previous segment in a misaligned manner, with the misalignment direction of the next segment opposite to that of the previous segment, but the misalignment distance being the same. The output single-mode fiber and the last segment of the coreless fiber are fused together axially. The central axes of the input and output single-mode fibers are collinear, and the cores of the input and output single-mode fibers are connected by a photolithographically written straight waveguide. A fiber Bragg grating is then optically etched along the straight waveguide. This invention uses femtosecond lasers to fabricate the FBG on the misaligned fiber structure, increasing the structure's strain response and making the strain sensitivity of the FBG on this structure higher than that of an FBG fabricated on ordinary silica optical fiber.