飞秒激光直写制备的长周期光纤光栅的温度稳定性及光谱调谐

Temperature Stability and Spectral Tuning of Long Period Fiber Gratings Fabricated by Femtosecond Laser Direct Writing.

作者信息

Viveiros Duarte, M M M de Almeida José, Coelho Luís, Vasconcelos Helena, M Maia João, A Amorim Vítor, A S Jorge Pedro, V S Marques Paulo

机构信息

Center for Applied Photonics, INESC TEC, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal.

Department of Physics and Astronomy, Faculty of Science, University of Porto, Rua do Campo Alegre, 4169-007 Porto, Portugal.

出版信息

Sensors (Basel). 2020 Jul 13;20(14):3898. doi: 10.3390/s20143898.

DOI:10.3390/s20143898

PMID:32668738

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC7412330/

Abstract

Long period fiber gratings (LPFGs) were fabricated in a standard single mode fiber (SMF-28e) through femtosecond (fs) laser direct writing. LPFGs with longer and shorter periods were fabricated, which allows coupling from the fundamental core mode to lower and higher order asymmetric cladding modes (LP and LP, respectively). For the grating periods of 182.7 and 192.5 µm, it was verified that the LP mode exhibits a TAP at approximately 1380 and 1448 nm in air and water, respectively. Characterization of the LPFGs subjected to high-temperature thermal treatment was accomplished. Fine-tuning of the resonance band's position and thermal stability up to 600 °C was shown. The temperature sensitivity was characterized for the gratings with different periods and for different temperature ranges. A maximum sensitivity of -180.73, and 179.29 pm/°C was obtained for the two resonances of the 182.7 µm TAP LPFG, in the range between 250 and 600 °C.

摘要

通过飞秒（fs）激光直写技术在标准单模光纤（SMF-28e）中制备了长周期光纤光栅（LPFG）。制备了周期较长和较短的LPFG，这使得能够分别从基模芯模耦合到较低阶和较高阶非对称包层模（分别为LP和LP）。对于周期为182.7和192.5 µm的光栅，验证了LP模在空气中和水中分别在约1380和1448 nm处呈现出横向衰减全反射（TAP）。完成了对经过高温热处理的LPFG的表征。展示了共振带位置的微调以及高达600°C的热稳定性。对不同周期的光栅以及不同温度范围的温度敏感性进行了表征。对于182.7 µm TAP LPFG的两个共振，在250至600°C范围内获得了最大灵敏度，分别为-180.73和179.29 pm/°C。