Morana A, Girard S, Marin E, Marcandella C, Paillet P, Périsse J, Macé J-R, Boukenter A, Cannas M, Ouerdane Y
Opt Lett. 2014 Sep 15;39(18):5313-6. doi: 10.1364/OL.39.005313.
We report a method for fabricating fiber Bragg gratings (FBG) resistant to very severe environments mixing high radiation doses (up to 3 MGy) and high temperatures (up to 230°C). Such FBGs have been written in two types of radiation resistant optical fibers (pure-silica and fluorine-doped cores) by exposures to a 800 nm femtosecond IR laser at power exceeding 500 mW and then subjected to a thermal annealing treatment of 15 min at 750°C. Under radiation, our study reveals that the radiation induced Bragg wavelength shift (BWS) at a 3 MGy dose is strongly reduced compared to responses of FBGs written with nonoptimized conditions. The BWS remains lower than 10 pm for temperatures of irradiation ranging from 25°C to 230°C without noticeable decrease of the FBG peak amplitude. For an applicative point of view, this radiation induced BWS corresponds to an additional error on the temperature measurements lower than 1.5°C, opening the way to the development of radiation-tolerant multi-point temperature sensors for nuclear industry.
我们报告了一种制造光纤布拉格光栅（FBG）的方法，该方法适用于混合高辐射剂量（高达3兆戈瑞）和高温（高达230°C）的非常恶劣的环境。通过用功率超过500毫瓦的800纳米飞秒红外激光照射，在两种抗辐射光纤（纯石英和氟掺杂纤芯）中写入了此类FBG，然后在750°C下进行15分钟的热退火处理。在辐射条件下，我们的研究表明，与在非优化条件下写入的FBG的响应相比，在3兆戈瑞剂量下辐射诱导的布拉格波长偏移（BWS）大幅降低。对于25°C至230°C的辐照温度，BWS保持低于10皮米，且FBG峰值幅度没有明显下降。从应用角度来看，这种辐射诱导的BWS对应于温度测量中低于1.5°C的额外误差，为核工业开发耐辐射多点温度传感器开辟了道路。
