Femtosecond Laser Fabrication of Long Period Fiber Gratings and Applications in Refractive Index Sensing
An improved point-by-point inscription method is proposed to fabricate long period fiber gratings (LPFGs) by using a laser operating at 800 nm with 35 fs duration pulses. The sensitivity to misalignment between the core and the focus is reduced by scanning a rectangular part on the fiber. LPFGs with an attenuation depth of 20 dB are achieved within the wavelength range of 1465-1575 nm. Characterization of the temperature sensitivity and thermal stability of the LPFGs is presented. A 5.6 nm wavelength shift and a 1.2 dB decrease in the attenuation peak are observed following heat treatment at 600 °C for 4 h. The fabricated LPFGs are used as refractive index sensors. The effect of heat treatment on the response of the LPFGs to refractive index changes is also studied.
B. Li et al., "Femtosecond Laser Fabrication of Long Period Fiber Gratings and Applications in Refractive Index Sensing," Optics & Laser Technology, Elsevier, Nov 2011.
The definitive version is available at https://doi.org/10.1016/j.optlastec.2011.04.011
Mechanical and Aerospace Engineering
Electrical and Computer Engineering
Ministry of Science and Technology of the People's Republic of China. 863 Program
National Natural Science Foundation (China)
Keywords and Phrases
Long Period Fiber Gratings; Refractive Index Sensor; Femtosecond lasers
Article - Journal
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