学术报告——Holographic ultrafast laser parallel micro/nano-processing
报告人：匡正 博士（University of Liverpool）
报告题目：Holographic ultrafast laser parallel micro/nano-processing
匡正博士简介：匡正博士分别于2006年和2010年获得英国利物浦大学工程学院硕士和博士学位，2010年博士毕业后留校成为利物浦大学工程系研究员（Research Fellow）一直工作至今。匡正博士在激光微纳制造，超快激光并行加工技术，激光引擎点火，超快激光整形和脉冲激光清洗技术等领域发表论文40余篇。匡正博士参与和主持过英国创新署（Innovation UK），英国工程及自然科学研究理事会（EPSRC - Engineering and Physical Sciences Research Council），欧洲区域发展基金（ERDF – Europe Regional Development Fund）和英技术战略署（TSB – Technology Strategy Board）支持的项目数个，相关科研经费总计几百万英镑。
Summary: During the last decade, ultrafast lasers have been employed for high precision surface micro-structuring of materials such as metals, semi-conductors and dielectrics with little thermal damage. Due to the ultra short pulse duration, unwanted thermal effects can be absent during the ultrafast laser material processing, hence achieving ‘cool processing’. To ensure the thermal-free material processing, the laser fluence (i.e. energy density) must be kept low, a few times above the material’s ablation threshold. However, many commercial laser systems provide about 100 times higher energy density. Significant attenuation of the laser output is hence required for many applications and causes a great deal of energy loss. With this limitation in mind, a holographic multi-beam ultrafast laser parallel processing technique, where the high energy density single output is split into many desired diffracted beams with arbitrary geometric arrangement, is demonstrated in Liverpool Laser Group, University of Liverpool. The multi-beam patterns are generated by phase modulation using computer generated holograms (CGHs) which are displayed on a Spatial Light Modulator (SLM). The ability to address these devices in real time and synchronize with scanning methods adds an additional flexibility to the processing. The results obtained demonstrate high precision micro/nano-fabrication of different kinds of materials with greatly increased processing efficiency and throughput, indicating many potential industrial applications.