Fabrication of long-period fiber gratings by focused irradiation of infrared femtosecond laser pulses

TLDR

The study investigates the thermal stability of fiber gratings fabricated by focused infrared femtosecond laser irradiation and proposes the technique as useful for producing gratings with superior aging characteristics. The fabricated long‑period fiber gratings retain their loss‑peak wavelength and transmittance after heat treatment below 500 °C, demonstrating high resistance to thermal decay.

Abstract

We have fabricated long-period fiber gratings by use of a novel technique using focused irradiation of infrared femtosecond laser pulses. We investigate the thermal stability of the fabricated fiber gratings. The values of the loss peak wavelength and the transmittance of the fiber gratings after heat treatment below 500 degrees C are the same as initial values before heat treatment. The fiber gratings that were fabricated by this technique have a high resistance to thermal decay. We propose that this technique will be useful for fabrication of fiber gratings with a superior aging characteristic.