Nano-Crystal and Microstructure Formation in Fluoride Photo-Thermo-Refractive Glass Using Chirp-Controlled Ultrafast Laser Bessel Beams

Yunjie Zhang , Xu Wang , Guodong Zhang , Razvan Stoian (1) , Guanghua Cheng

1 LHC - Laboratoire Hubert Curien [Saint Etienne]

Nano-crystals were formed in the exposed regions of photo-thermo-refractive glass undergoing irradiation with zeroth order chirp-controlled ultrafast laser Bessel beams and subsequent heat treatment. Effects of various writing powers, pulse durations and heat treatment time on the distribution and the size of the nano-crystals were investigated. The results show that nano-crystals’ distribution depended on the laser power density spatial shape, while the size of the nano-crystals is quasi-independent. However, the average diameter of the nano-crystals was affected by the heat treatment time, decreasing from 175 to 105 nm with the time halved. In addition, using crystallographic characterization by X-ray diffraction, the nano-crystal composition in the laser-exposed regions was detected to be sodium fluoride.

Domains: Engineering Sciences [physics]; Optics / Photonic

Yunjie Zhang, Xu Wang, Guodong Zhang, Razvan Stoian, Guanghua Cheng. Nano-Crystal and Microstructure Formation in Fluoride Photo-Thermo-Refractive Glass Using Chirp-Controlled Ultrafast Laser Bessel Beams. Nanomaterials, 2021, 11 (6), pp.1432. ⟨10.3390/nano11061432⟩. ⟨ujm-03242414⟩