Femtosecond laser point-by-point inscription of helical-sampled fiber Bragg gratings

Opt Lett. 2022 Feb 15;47(4):786-789. doi: 10.1364/OL.447085.

Abstract

In this Letter, a helical-sampled fiber Bragg gratings (HSFBGs) fabrication using a femtosecond laser point-by-point (PBP) technique is proposed. The unique helical structure generates sampled gratings owing to its periodicity. A simple, single-step method for inscription of the sampled gratings is described. The effects of geometrical parameters, including length of grating, helical diameter, helical pitch, and off-axis distance on the resonances are studied, and a series of comb-like spectra are obtained.