Bragg gratings written in multimode borosilicate fibers using ultrafast infrared radiation and a phase mask

摘要

Inscription of Bragg grating structures is reported in inexpensive multimode borosilicate fibers using femtosecond pulse duration 800 nm infrared radiation and a phase mask. Thermal annealing of the gratings up to 700 ℃ reveals a behavior similar to Type I-IR gratings made in silica fiber with ultrafast infrared radiation. A portion of the index modulation of the grating is stable up to 500 ℃. Below 100 ℃, the wavelength shift of the Bragg grating is characterized by ～ 12 pm/℃ slope. Above 300 ℃, the wavelength shift is ～ 5 pm/℃.