Chinese Optics Letters, 2019, 17 (8): 081405, Published Online: Jul. 18, 2019
Ultrafast dynamics of three types of simultaneous shockwaves and filament attenuation in femtosecond laser multi-pulse ablation of PMMA Download: 747次
140.7090 Ultrafast lasers 320.7120 Ultrafast phenomena 350.5400 Plasmas 350.3390 Laser materials processing
Abstract
Cylindrical shockwaves inside polymethyl methacrylate (PMMA) generated simultaneously with two hemispherical shockwaves induced by a femtosecond Gaussian beam laser were investigated using an ultrafast pump–probe imaging technique. The evolutions of these three shockwaves with probe delay and incident pulse number have been systematically analyzed. The plasma intensity and filament length in the center of cylindrical shockwave both decayed with pulse number. Moreover, the self-focused filament moved downstream towards the output surface with an increased pulse number. The experimental results and mechanism illustrated that energy deposition was suppressed by a degraded nonlinear effect due to a pre-ablated structure in multi-pulse irradiation.
Guoyan Wang, Lan Jiang, Jingya Sun, Jie Hu, Qingsong Wang, Ming Li, Yongfeng Lu. Ultrafast dynamics of three types of simultaneous shockwaves and filament attenuation in femtosecond laser multi-pulse ablation of PMMA[J]. Chinese Optics Letters, 2019, 17(8): 081405.