Author Affiliations
Abstract
Laser Micro/Nano Fabrication Laboratory, School of Mechanical Engineering, Beijing Institute of Technology, Beijing 100081, China
We report a simple, cost-effective and repeatable method for fabricating a large area and uniform substrate for surface-enhanced Raman scattering (SERS). The silicon, micromachined by a femtosecond laser, is coated with gold film and then treated through the dewetting process. The morphology shows a higher electric field enhancement due to light trapping. The enhancement factor of the SERS substrate is 9.2×107 with a 5 nm-thick film coated. Moreover, it also exhibits a uniform signal through Raman mapping and chemical stability with the greatest intensity deviation of 6% after a month. The proposed technique provides an opportunity to equip microchips with the SERS capabilities of high sensitivity, chemical stability, and homogeneous signals.
240.6695 Surface-enhanced Raman scattering 140.7090 Ultrafast lasers Chinese Optics Letters
2015, 13(11): 111401
Author Affiliations
Abstract
The manipulation of the subpulse number, pulse delay, and pulse energy distribution of an ultrafast laser enables electron dynamics control by changing absorptions, excitations, ionizations, and recombinations of electrons, which can result in smaller, cleaner, and more controllable structures. This letter experimentally reveals that ablation sizes and recasts can be controlled by shaping femtosecond pulse trains to adjust transient localized electron dynamics, material properties, and corresponding phase change mechanisms.
140.3390 Laser materials processing 320.7130 Ultrafast processes in condensed matter, including semiconductors 320.5540 Pulse shaping Chinese Optics Letters
2013, 11(4): 041403
北京理工大学先进加工技术国防重点学科实验室， 北京 100081
飞秒激光具有超快、超强的特性，在微孔加工中有着独特的优势，尤其是针对高品质、大深径比的微孔加工有着不可替代的作用。介绍了超短脉冲激光微孔加工的优势以及研究意义，综述了近十几年来基于超短脉冲激光的微孔加工研究现状，并讨论了材料、激光脉冲参数、加工方式和加工环境等因素对超短脉冲激光微孔加工的影响。指出了现阶段超短脉冲激光微孔加工的应用前景，并总结了超短脉冲激光微孔加工当前所面临的挑战，以及今后的研究重点。
超快光学 超短脉冲激光 微孔加工 飞秒脉冲 脉冲序列
