High temperature-sensitivity sensor based on long period fiber grating inscribed with femtosecond laser transversal-scanning method

• 来源期刊: 中国光学快报（英文版）
• 年，卷（期）: 2017,（9）
• 页码范围: 51-55
• 页数: 5页
• 语种: 英文
• DOI: 10.3788/COL201715.090602

摘要

We propose a high temperature-sensitive long period fiber grating (LPFG) sensor fabricated by using the femtosecond laser transversal-scanning method.The femtosecond pulses scan over the whole fiber core and some part of the cladding region;the modified regions are more extended.It is found that the LPFG-Ⅰ fabricated by the transversal-scanning method shows higher temperature sensitivity and better temperature uniformity than that of LPFG-Ⅱ written by the femtosecond laser point-by-point method.The LPFG-Ⅰ with a temperature sensitivity of 75.96 pm/℃ in the range of 25℃-400℃ is measured.Moreover,in the range from 400℃ to 800℃,a higher temperature sensitivity of 148.64 pm/℃ and good linearity of 0.99 are achieved,while the temperature sensitivity of LPFG-Ⅱ is only 95.55 pm/℃.LPFG-Ⅰ exhibits better temperature characteristics,which,to the best of our knowledge,has the highest sensitivity in silica fiber temperature sensors.