Characteristics of 1064 nm picosecond laser induced filamentary tracks and damages in sapphire. (August 2019)

• Record Type: Journal Article
• Authors: Amina, ; Ji, Lingfei; Yan, Tianyang; Wang, Yuheng; Li, Lin
• Is Part Of: Optics & laser technology. Volume 116(2019)
• Page Start: 232
• Page End: 238
• Publication Date: 2019-08
• Subjects: Transparent material -- Microfabrication -- Picosecond laser -- Sapphire -- Filamentation; Optics -- Periodicals; Lasers -- Periodicals; Electronic journals; 621.366
• DOI: 10.1016/j.optlastec.2019.03.019
• Languages: English
• ISSNs: 0030-3992

Abstract

Highlights: Understanding the characteristics of picosecond filamentation in sapphire. Compared laser parameter influence on filamentation in terms of lateral size and modified zones length. Increasing pulse number induces cracks but has no significant effect on filamentary track. Filamentary track length increases with increasing pulse energy and decreasing repetition rate. Abstract: The induction of structural modifications by focused laser pulses in bulk transparent materials is a versatile technique for the microfabrication of photonic devices. In this paper, the influence of repetition rate, pulse energy and number of pulses was studied by comparing picosecond laser induced structural modifications in sapphire. The observed structural modifications consisted of a uniaxial void zone surrounded by smooth refractive index changes, and micro cracks followed by a submicrometer filamentary track. The number of laser pulses was found to be the primary factor in causing cracks surrounding the focal volume while pulse repetition rate and pulse energy were observed to have minor roles in these cracks. However, with increasing repetition rate, length of the filamentary track decreased, whereas no significant difference was observed in the length by changing number of pulses. Furthermore, filamentary track length has increased with the increase of laser energy. At 107 µJ energy, a maximum filamentary track of length 1180 µm was observed.