Inscription and Thermal Stability of Fiber Bragg Gratings in Hydrogen-Loaded Optical Fibers Using a 266 nm Pulsed Laser
Xiangxi Zhu,
Zixuan Xin,
Haoming Zhu,
Hongye Wang,
Xin Cheng,
Hwa-Yaw Tam,
Hang Qu,
Xuehao Hu
Affiliations
Xiangxi Zhu
Research Center for Advanced Optics and Photoelectrics, Department of Physics, College of Science, Shantou University, Daxue Lu 243, Shantou 515063, China
Zixuan Xin
Research Center for Advanced Optics and Photoelectrics, Department of Physics, College of Science, Shantou University, Daxue Lu 243, Shantou 515063, China
Haoming Zhu
Research Center for Advanced Optics and Photoelectrics, Department of Physics, College of Science, Shantou University, Daxue Lu 243, Shantou 515063, China
Hongye Wang
The Key Laboratory of In-Fiber Integrated Optics of Ministry of Education, College of Physics and Optoelectronic Engineering, Harbin Engineering University, Harbin 150001, China
Xin Cheng
Department of Electrical and Electronic Engineering, The Hong Kong Polytechnic University, Kowloon, Hong Kong SAR 997700, China
Hwa-Yaw Tam
Department of Electrical and Electronic Engineering, The Hong Kong Polytechnic University, Kowloon, Hong Kong SAR 997700, China
Hang Qu
Research Center for Advanced Optics and Photoelectrics, Department of Physics, College of Science, Shantou University, Daxue Lu 243, Shantou 515063, China
Xuehao Hu
Department of Electromagnetism and Telecommunication, University of Mons, Boulevard Dolez 31, 7000 Mons, Belgium
Fiber Bragg gratings (FBGs) have gained substantial research interest due to their exceptional sensing capabilities. Traditionally, FBG fabrication has required the use of pre-hydrogenated fibers and high-cost laser systems such as excimer lasers at 193 nm or femtosecond lasers. In this study, we present the first instance of FBG inscription in hydrogen-loaded, standard single-mode silica optical fibers using a more affordable 266 nm solid-state pulsed laser combined with a scanning phase mask lithography technique. We systematically explored the effects of pulse energy and scanning speed on the quality and spectral characteristics of the gratings, achieving reflectivities as high as 99.81%. Additionally, we tracked the spectral evolution during the FBG inscription process, demonstrating uniform growth of the core mode. We also investigated the stability of the core mode during a 24-h thermal annealing process up to 150 °C. The sensitivity was 10.7 pm/°C in the range of 0 to 130 °C. Furthermore, strain measurement was conducted based on the FBG annealed at 100 °C, showing a sensitivity of 0.943 pm/µε in the range of 0 to 1667 µε.
