High-precision point-by-point fiber Bragg grating inscription

The paper presents a novel multi-pass point-by-point method for high-precision inscription of fiber Bragg gratings with a femtosecond laser radiation. The dynamics of the gratings formation is demonstrated in comparison with the classical method of UV-radiation inscription. It is shown that due to the feasibility of the inscription dynamics control, it is possible to fabricate high-precision Bragg gratings with specified parameters and a high degree of reproducibility. The proposed technique is demonstrated to be a convenient tool for studying the processes occurring in glass during multiphoton absorption of laser radiation.