Product Code: ICA13_M304

Structuring Features of Micro- and Nano-Ripples Induced by Oblique Incident Linear Polarized Femtosecond Laser Irradiating Metal Surface
Authors:
Xiang Ming Dong, Institute of Laser Engineering, Beijing University of Technology, China; Beijing Peoples Republic of China
Haiying Song, Institute of Laser Engineering, Beijing University of Technology, China; Beijing Peoples Republic of China
Song Liu, Institute of Laser Engineering .Beijing University of Technology; Beijing Peoples Republic of China
Shibing Liu, Institute of Laser Engineering, Beijing University of Technology, China; Beijing Peoples Republic of China
Presented at ICALEO 2013

The periodic ripple structures with micro- and nano-scales on the metal surface are fabricated experimentally by using an oblique incident linear polarized femtosecond laser pulse with 800nm wavelength. The structuring features show a material difference in the s- and p-polarized laser irradiations. Besides the ripples are perpendicular to the polarized direction of applied laser, in the p-polarized laser irradiation the interspace between ripples increases with the incident angle when it exceeds a threshold angle , and differently the interspace is unaltered with the incident angle in the s-polarized laser irradiation. Especially, when the incident angle is larger than the threshold angle, the spacial structured cycle (SSC) is larger than the wavelength of incident laser. To explain these phenomena we employ the Coulomb ablation resulted from phase-locked Langmuir wave resonance to the periodic structure formation and present an expression for evaluating SSC of the ripples. For the dependence of SSC on the incident angle in the p-polarized laser irradiation, we propose a resonance absorption mechanism, by which the observations experimentally can be excellently interpreted.