大视场复眼微光学元件的飞秒激光微加工方法研究

With small size, light weight , integrated, large field of view and high sensitivity，artificial compound eyes have important applications in the detection of space debris , a full range of missiles guiding, unmanned aerial vehicles and robot vision and so. Whereas, the traditional microfabrication processes are difficult to meet the needs of manufacturing of high precision micro-optical elements with such great arch of highly complex three-dimensional configurations. This project proposes a femtosecond laser wet etch new method for the wide-view micro-optic components manufacturing. It will carry out the studying in transient mechanism of interaction between femtosecond laser and materials, modification mechanism of laser fine-tuning materials, chemical wet etching of material modified zone, micromachining process of artificial compound eyes，and gradually clarify the mechanism of activated, modified chemical bond in material absorbing the photon energy, precisely regulate the interaction between laser and material to achieve targeted modification.The aim of this study is to obtain new principles and methods of energy deposition controls of light-affected zone material during the laser zone-by-point scanning, chemical wet etching and polishing, to improve the efficiency, accuracy and quality of micro-optical components,and getting a breakthrough in manufacturing the high-arch, complex three-dimensional configuration micro-optics, exploring a new method of femtoscond laser micormachining of the high-performance compound eye.

人工复眼微光学元件具有体积小、重量轻、阵列化、视场大、灵敏度高等优点，在空间碎片探测、GPS姿态传感、导弹全方位制导、无人机及机器人视觉等方面均有十分重要的应用价值，而传统微加工工艺还难以制备这种大拱高复杂三维构型的高精密微光学元件。本项目提出一种大视场复眼微光学元件的飞秒激光湿法刻蚀新方法，拟深入研究飞秒激光与材料作用的瞬态机理、激光精细调控材料改性机制、改性区材料的化学刻蚀方法和人工复眼微光学元件微加工工艺，并在研究中逐步澄清激光加工中材料吸收光子能量对化学键的激活、改性机制，精确调控光与物质相互作用实现材料的目标靶向改性，获得激光逐点扫描控制光影响区材料能量沉积与化学湿法刻蚀与抛光的原理与方法，提高微光学元件的飞秒激光微加工效率、精度和质量，突破大拱高复杂三维构型微光学元件制造的技术瓶颈，探索和形成高性能人工复眼微光学器件的飞秒激光微加工新方法。

复眼微光学结构由于具有视场大、像差小、灵敏度高及动态物体捕捉等卓越的光学性能被广泛地运用于照明工程、雷达系统、微型飞行器、复眼摄像机、夜视仪等国防及民用设备之中。针对各类应用中对高性能人工复眼器件的需求，本项目提出了大视场复眼微光学结构的飞秒激光湿法刻蚀微加工的新方法。项目深入研究了飞秒激光与材料作用的瞬态机理、激光精细调控材料改性机制、改性区材料的化学刻蚀方法，形成人工复眼微光学元件微加工工艺的理论依据，通过精确调控光与物质相互作用的动态过程实现材料的目标靶向改性，提高刻蚀速率和刻蚀区表面特征质量，可获得面形参数可控、面形质量优异的微刻蚀区。项目分别研究了飞秒激光单脉冲扫描间接法制备复眼微光学结构和飞秒激光多脉冲曲面湿法刻蚀技术制备高质量复眼微光学结构，运用单脉冲诱导烧蚀玻璃表面、HF诱导微透镜高效制作大面阵、高质量的微透镜阵列模板，运用表面赋形热压方法，在聚合物薄膜上制作出高质量人工复眼结构，变形率在0.2-0.4之间可调，填充率>99%，具有表面形貌好、加工效率高、成像视场角大等突出优势；对比飞秒激光作用在材料倾斜面/曲面情形下的烧蚀特性及对湿刻生成微透镜形貌的影响，利用凹面玻璃透镜作为基准面，在其上直接形成飞秒激光诱导区阵列，进而湿法刻蚀获得带有凹型曲面的3D微透镜模板，例如热固型聚合物PDMS翻模制作高度2.5mm，直径6mm，填充比100%的真3D的人工复眼微结构，测量获得其成像视场角达160°，成像质量优良。通过本项目的研究，利用对飞秒激光与材料相互作用过程的精确调控，化学湿法刻蚀过程及复制工艺过程的参数优化，逐步形成了利用飞秒激光湿法刻蚀技术制备高质量、大视场人工复眼微光学元件的新方法。