Electromagnetism and Telecom Department, University of Mons, 7000 Mons, Belgium.
Belgian Nuclear Research Centre (SCK-CEN), 2400 Mol, Belgium.
Sensors (Basel). 2022 Dec 21;23(1):39. doi: 10.3390/s23010039.
We investigated the gamma radiation response of fiber Bragg gratings (FBGs) inscribed in a few-mode polymer optical fiber. The fiber had a graded-index CYTOP core of 20 µm and XYLEX overclad of 250 µm in diameter. Four FBGs were exposed to gamma radiation during four irradiation sessions at a 5.3 kGy/h dose rate. The FBGs showed a linear Bragg wavelength shift with the received dose with a mean sensitivity of -3.95 pm/kGy at 43 °C. The increased temperature provides a rise in the sensitivity: it reached -10.6 pm/kGy at 58 °C. After irradiation, the FBGs showed partial recovery, which increased with the received dose. Furthermore, the FBG's reflection power decreased with the dose. This attenuation is mainly due to insertion losses caused by the radiation induced attenuation in the CYTOP fiber. Linear response to the received dose makes CYTOP FBGs attractive for gamma radiation dosimetry. However, temperature dependence of the sensitivity should be compensated in practical applications.
我们研究了刻写在多模聚合物光纤中的光纤布拉格光栅（FBG）对伽马辐射的响应。光纤的梯度指数 CYTOP 芯层直径为 20 µm，XYLEX 外覆层直径为 250 µm。四个 FBG 在 5.3 kGy/h 的剂量率下进行了四次辐照，以暴露于伽马辐射下。FBG 表现出与接收剂量的线性布拉格波长移动，在 43°C 下平均灵敏度为-3.95 pm/kGy。温度升高会提高灵敏度：在 58°C 下达到-10.6 pm/kGy。辐照后，FBG 表现出部分恢复，随着接收剂量的增加而增加。此外，FBG 的反射功率随剂量降低。这种衰减主要是由于 CYTOP 光纤中辐射诱导衰减引起的插入损耗。对接收剂量的线性响应使得 CYTOP FBG 成为伽马辐射剂量测定的有吸引力的选择。然而，在实际应用中，应该补偿灵敏度的温度依赖性。
