Polarization influence on femtosecond laser-induced surface damage and electron plasma ultrafast dynamics in sapphire
Abstract
This study investigates the impact of the polarization direction of femtosecond laser relative to the sapphire crystal axis on surface damage threshold and ultrafast electron plasma dynamics, which were characterized by using damage area extrapolation and pump–probe shadowgraphy methods, respectively. It was found that the surface damage threshold, electron plasma density, and nonlinear focal-point position exhibit π/2 periodic oscillations with changes in the laser polarization angle when the laser is incident along the a axis. However, such dependence is not obvious when the laser is incident along the c axis. It is proved from the absorption coefficient and relaxation time that the periodic variation is relative to the equivalent electron mass and crystal symmetry. These findings provide important insights into optimizing femtosecond laser processing of anisotropic materials such as sapphire.
Article Details
Journal Info
Journal of Applied Physics
American Institute of Physics
Authors (9)
Xiao Niu
Daqi Zhang
Key Laboratory of Physical Electronics and Devices, Ministry of Education and Shaanxi Key Laboratory of Information Photonic Technique, School of Electronic Science and Engineering, Xi'an Jiaotong University , Xi'an,
Tao Chen
Yu Zhang
Xiangya Hospital, Central South University Changsha China
Tianlun Shen
Key Laboratory of Physical Electronics and Devices, Ministry of Education and Shaanxi Key Laboratory of Information Photonic Technique, School of Electronic Science and Engineering, Xi'an Jiaotong University , Xi'an,
Fengqin Huang
Key Laboratory of Physical Electronics and Devices, Ministry of Education and Shaanxi Key Laboratory of Information Photonic Technique, School of Electronic Science and Engineering, Xi'an Jiaotong University , Xi'an,
Yun Zhong
Jinhai Si
Key Laboratory for Physical Electronics and Devices of the Ministry of Education and Shaanxi Key Lab of Photonic Technique for Information, School of Electronics Science and Engineering, Faculty of Electronic and Information Engineering, Xi’an Jiaotong University , Xi’an 710049,
Xun Hou
Key Laboratory for Physical Electronics and Devices of the Ministry of Education and Shaanxi Key Lab of Photonic Technique for Information, School of Electronics Science and Engineering, Faculty of Electronic and Information Engineering, Xi’an Jiaotong University , Xi’an 710049,