Femtosecond pulse laser ablation of sapphire in ambient air

Femtosecond laser ablation of sapphire on different crystallographic facet planes by single and multiple laser pulses irradiation

“…The pulse energy of the surface damage on sapphire on c-plane by single laser pulse irradiation was about 1.31 mJ focused with an objective lens with a NA¼0.30. The threshold fluence of femtosecond laser ablation of sapphire for single pulse irradiation calculated by Liu [18] and Wang et al [7] is described in the following parts.…”

“…The ablation depth of the crater increased with the number of laser pulses when the energy fluence was more than the ablation threshold fluence [5,7]. In the case of microgrooves fabrication on sapphire, low energy fluence was preferred due to high machining surface quality requirements [19].…”

“…Recently, the ultrashort laser ablation of sapphire has been attracting much attention because ultrashort laser ablation can produce precise, well-defined micrometer-sized structures in materials that cannot be processed with nanosecond pulsed lasers. A number of studies on the ultrashort laser ablation of sapphire have been carried out [3][4][5][7][8][9], and a mechanism for the ultrashort laser ablation of sapphire has been proposed [4,5,7,[9][10][11]. In ultrashort laser ablation of sapphire, two ablation phases were observed.…”

“…As sapphire is inert to most types of wet chemical and dry etching, laser ablation has been proposed as a potential machining method. The interaction of laser pulses with sapphire material has been investigated for many years [1][2][3][4][5][6][7]. However, a thermal effect is unavoidable even with ultraviolet laser processing [6].…”

Large volume ablation of Sapphire with ultra-short laser pulses

“…A comparison in performance between sub-picosecond and picoseconds pulses was reported, showing an improved quality for sub-ps pulses [8]. Furthermore, the effect of the number of pulses and their energy on the surface damage threshold of Sapphire and on the depth and diameter of drilled holes has been investigated [9,10]. In addition, an investigation of the laser scan speed and focal position on the quality of cutting, was also reported [11].…”