Title :
In-Fiber Grating Fabricated by Femtosecond Laser Direct Writing for Strain Sensing
Author :
Quandong Huang ; Yongqin Yu ; Shuangchen Ruan ; Xuejin Li ; Xue Chen ; Yufeng Zhang ; Wen Zhou ; Chenlin Du
Author_Institution :
Coll. of Electron. Sci. & Technol., Shenzhen Univ., Shenzhen, China
Abstract :
In this letter, we reported long period fiber gratings (LPFGs) fabricated by femtosecond laser pulses direct writing in grapefruit microstructured fiber. The mode field distribution and dispersion property of this fiber was analyzed by finite-element method. Two LPFGs were fabricated with different periods of 230 and 250 μm, the resonant dips appeared at the wavelengths of 1325.8 and 1449.4 nm, respectively. In addition, sensing characteristics of the LPFG with the period of 250 μm were investigated in theory and experiment. The experimental results show that the strain and temperature sensitivities are 1.88 pm/με and 0.267 pm/°C, respectively. It indicates that the temperature cross sensitivity is as low as 0.142 με/°C.
Keywords :
diffraction gratings; fibre optic sensors; finite element analysis; high-speed optical techniques; laser materials processing; optical fibre dispersion; optical fibre fabrication; strain sensors; LPFG; femtosecond laser direct writing; fiber dispersion property; finite element method; grapefruit microstructured fiber; in-fiber grating fabrication; long period fiber gratings; mode field distribution; strain sensing; strain sensitivity; temperature sensitivity; Fiber gratings; Fiber lasers; Optical fiber dispersion; Optical fiber sensors; Sensitivity; Strain; Temperature sensors; Long period fiber gratings; Long period fiber gratings,; femtosecond laser fabrication; fiber optic sensor; microstructured fiber;
Journal_Title :
Photonics Technology Letters, IEEE
DOI :
10.1109/LPT.2015.2414944
