Direct Femtosecond Laser Inscription of High-Order Bragg Gratings in Fluoroaluminate Glass Fiber
oleh: Lin She, Niannian Xu, Pengfei Wang, Jiquan Zhang, Mo Liu, Nian Lv, Ruoning Wang, Zhenrui Li, Shijie Jia, Shunbin Wang, Gerald Farrell, Weimin Sun
| Format: | Article |
|---|---|
| Diterbitkan: | IEEE 2022-01-01 |
Deskripsi
This letter reports the fabrication of fiber Bragg gratings (FBGs) within in-house fabricated fluoroaluminate (AlF<sub>3</sub>) glass fibers using femtosecond (fs) laser inscription at 800 nm. The grating strength of the FBGs was investigated for different pulse energies and different orders, and a 3rd-order FBG with Bragg wavelength at 1557 nm was found to have the highest reflectivity of 99.5%. In addition, the reflectivity of the mid-IR grating peaks for different orders was also studied, and a 2nd-order FBG with a reflectivity of 98.8% was obtained at 2864 nm. Finally, the temperature characteristics of a mid-IR FBG were studied between 30 °C and 150 °C, showing a linear wavelength dependence and an excellent stability for the refractive index modulation. Such highly reflectivity FBGs in AlF<sub>3</sub> fiber have significant potential for applications in the development of compact all-fiber mid-IR fiber lasers.