Anisotropy modulations of femtosecond laser pulse induced periodic surface structures on silicon by adjusting double pulse delay

Authors

• Weina Han, Beijing Institute of Technology
• Lan Jiang, Beijing Institute of Technology
• Xiaowei Li, Beijing Institute of TechnologyFollow
• Qingsong Wang, Beijing Institute of Technology
• Hao Li, Beijing Institute of Technology
• Yongfeng Lu, University of Nebraska-LincolnFollow

Document Type

Article

Date of this Version

6-30-2014

Citation

Optics Express 22:13 (2014), pp. 15820 - 15828; doi: 10.1364/OE.22.015820

Comments

Copyright © 2014 Optical Society of America. Used by permission.

Abstract

We demonstrate that the polarization-dependent anisotropy of the laser-induced periodic surface structure (LIPSS) on silicon can be adjusted by designing a femtosecond laser pulse train (800 nm, 50 fs, 1 kHz). By varying the pulse delay from 100 to 1600 fs within a double pulse train to reduce the deposited pulse energy, which weakens the directional surface plasmon polarition (SPP)-laser energy coupling based on the initial formed ripple structure, the polarization-dependent geometrical morphology of the LIPSS evolves from a nearly isotropic circular shape to a somewhat elongated elliptical shape. Meanwhile, the controllable anisotropy of the two-dimensional scanned-line widths with different directions is achieved based on a certain pulse delay combined with the scanning speed. This can effectively realize better control over large-area uniform LIPSS formation. As an example, we further show that the large-area LIPSS can be formed with different scanning times under different pulse delays.