Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
5356503 | Applied Surface Science | 2016 | 5 Pages |
Abstract
The formation process and mechanism of subwavelength ripples were studied upon irradiation of ZnO by a femtosecond laser (800Â nm, 50Â fs, 1Â kHz). An abnormally asymmetrical grating-splitting phenomenon was discovered. At relatively high laser fluences (FÂ =Â 0.51-0.63Â J/cm2), near-wavelength ripples were split asymmetrically to create subwavelength laser-induced periodic surface structures (LIPSS) with dual gaps (â¼230Â nm and â¼430Â nm) on the primary grooves. At relatively low laser fluences (FÂ =Â 0.4-0.45Â J/cm2), near-wavelength ripples were split symmetrically, leading to the formation of uniform subwavelength structures with a period of â¼340Â nm. The splitting phenomena are related to the varying laser beam dose induced by the overlapping during line scanning. The two grating-splitting types further imply that the dominated mechanism for LIPSS formation may be changed under different processing conditions.
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Related Topics
Physical Sciences and Engineering
Chemistry
Physical and Theoretical Chemistry
Authors
Pin Feng, Lan Jiang, Xin Li, Kaihu Zhang, Xuesong Shi, Bo Li, Yongfeng Lu,