Microsphere femtosecond laser sub-50 nm structuring in far field via non-linear absorption
基于非线性吸收的远场亚50nm飞秒微球激光结构
非線形吸収に基づく遠視野サブ50 nmフェムト秒微小球レーザ構造
비선형 흡수에 기반한 원거리 50nm 비초 마이크로볼 레이저 구조
Estructura láser de microesferas femtosegundas de campo lejano de sub50 nm basadas en absorción no lineal
Structure laser microsphère à champ lointain Sub - 50nm femtoseconde basée sur l'absorption non linéaire
структура дальнего суб50нм фемтосекундного микроволнового лазера на основе нелинейного поглощения
Zhenyuan Lin 林真源 ¹ ³, Kuan Liu 刘宽 ², Tun Cao 曹暾 ², Minghui Hong 洪明辉 ¹ ³
¹ Pen-Tung Sah Institute of Micro-Nano Science and Technology, Xiamen University , Xiamen 361102, China
中国 厦门 厦门大学萨本栋微米纳米科学技术研究院
² School of Optoelectronic Engineering and Instrumentation Science, Dalian University of Technology, Dalian 116024, China
中国 大连 大连理工大学光电工程与仪器科学学院
³ Department of Electrical and Computer Engineering, National University of Singapore, 4 Engineering Drive 3, 117576, Singapore
Creation of arbitrary features with high resolution is critically important in the fabrication of nano-optoelectronic devices. Here, sub-50 nm surface structuring is achieved directly on Sb2S3 thin films via microsphere femtosecond laser irradiation in far field.
By varying laser fluence and scanning speed, nano-feature sizes can be flexibly tuned. Such small patterns are attributed to the co-effect of microsphere focusing, two-photons absorption, top threshold effect, and high-repetition-rate femtosecond laser-induced incubation effect.
The minimum feature size can be reduced down to ~30 nm (λ/26) by manipulating film thickness. The fitting analysis between the ablation width and depth predicts that the feature size can be down to ~15 nm at the film thickness of ~10 nm. A nano-grating is fabricated, which demonstrates desirable beam diffraction performance.
This nano-scale resolution would be highly attractive for next-generation laser nano-lithography in far field and in ambient air.
