title: Anisotropy modulations of femtosecond laser pulse induced periodic surface structures on silicon by adjusting double pulse delay.
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.
authors: Weina
authors: W
authors: Han
authors: Lan
authors: L
authors: Jiang
authors: Xiaowei
authors: X
authors: Li
authors: Qingsong
authors: Q
authors: Wang
authors: Hao
authors: H
authors: Li
authors: YongFeng
authors: Y
authors: Lu