改进型飞秒写制长周期光纤光栅及其高温特性  

Improved femtosecond laser fabrication of long period fiber gratings and corresponding applications in high temperature measurement

作　　者：李海涛[1] 孙小燕[1] 董欣然[1] 段吉安[1] 周剑英[1] 胡友旺[1] 王聪[1] 

机构地区：[1]中南大学高性能复杂制造国家重点实验室,湖南长沙410083

出　　处：《光电子．激光》2014年第10期1859-1864,共6页Journal of Optoelectronics·Laser

基　　金：国家重点基础研究发展计划"973"项目(2011CB013000);国家自然科学基金(91123035;91323302;51335011;51005250);教育部"新世纪优秀人才支持计划"(NCET-12-0548)资助项目

摘　　要：基于双CCD对光纤夹持运动系统进行五维初步定位,通过计算机控制运动平台和飞秒激光,采用改进型的逐点扫描方法在未经载氢的SMF-28光纤纤芯区域进行矩形区域扫描,降低了逐点刻写法对聚焦光点与纤芯对准的敏感性,成功刻写出在1 250-1 400nm波段主谐振峰值达-19dB的长周期光纤光栅（LPFG）,光栅长为16.5mm。对写制的LPFG进行高温特性分析,实验获得其在300-800℃范围主谐振峰的温度响应灵敏度达到139.27pm/℃,线性度为0.993。研究表明：改进型的飞秒激光逐点扫描方法稳定可靠,刻写的光栅尺寸小,并且光栅在高温范围有很高的响应灵敏度,特别适用于高温检测。In order to improve the high temperature sensing properties of the long period fiber gratings（LPFGs）,an improved point-by-point inscription method is proposed to fabricate LPFGs.The method principle is scanning a rectangular part on the fiber core to reduce the sensitivity to misalignment between the core and the focus.An LPFG is inscribed successfully in no-hydrogen-loaded SMF-28 fiber using this method by controlling femtosecond laser,with the alignment of the fiber core systems containing dual-CCDs and high-precision electric displacement platform.And the attenuation depth of-19 dB within the wavelength range of 1250-1400 nm is obtained in the LPFG whose length is 16 mm.Then,high temperature characteristics experiment is performed on the LPFG by a high temperature tube furnace.An sensitivity of 139.27pm/℃and a linearity of 0.993 within the temperature range of 300-800℃are achieved.It is demonstrated that the LPFGs fabricated by the improved point-by-point inscription method are very suitable for the high temperature measurement.

关 键 词：飞秒激光 长周期光纤光栅(LPFG) 高温检测 改进型的逐点扫描方法 

分 类 号：TN253[电子电信—物理电子学]