基于飞秒激光复合技术的折衍型红外微光学元件研究

Hybrid refractive-diffractive micro-optics elements which possess excellent aplanatic, achromatic optical properties can replace the common optical element set to miniaturize the light path system. The large hardness, thermal instability problem and the fragility of infrared optical material which can be applied to infrared sensing and image and cause the microstructure roughness problem make the fabrication of micro-optics elements based on infrared material processing become a challenging puzzle. Considering the applied value and significance of infrared micro-optics elements, the femtosecond laser complex technologies have been put forward to challenge this issue. The femtosecond laser combined technology includes two technological path: Femtosecond laser induced micro-explosion and Top-down molecular orientation dissolution. In practical implementation process, femtosecond laser induced the infrared materials damage by the mean of multiphoton absorption effect is adopted as the fabrication breakthrough exit. In principle, this technology realizes the breakthrough of the key scientific problem " the highly unbalanced light reaction law occurred in micro-nano scale area under the weak-limitted condition". Finally, the hybrid refractive-diffractive infrared micro-optics elements with the three-dimensional complex topography and excellent optical quality can be fabricated through the femtosecond laser combined technology. On this basis, the micro-optics elements will be applied to the optical imaging and optical focus of infrared laser and micro system prototype device with excellent optical quality and commercial product can be obtained

折衍混合型微光学元件具备优异的消球差、消色差等光学特性，单一元件可以实现普通元件透镜组的功能。针对于红外传感、红外成像等应用的红外材料，其硬度大、热学性质不稳定、材料的硬脆性引发微结构制作的粗糙度问题，使得基于红外材料的折衍混合型微光学元件加工成为了一个颇具挑战性难题。本项目提出利用飞秒激光复合技术对这一难题进行挑战。具体以飞秒激光诱导红外材料多光子损伤为突破口，通过对“弱受限微纳尺度区域内发生的高度非平衡光反应规律”这一关键科学问题的突破，通过飞秒激光诱导微爆炸路线和Top-down分子定向溶解路线这一复合技术来制备三维复杂形貌、高光学质量的折/衍射型红外微光学元件。在此基础上，将微光学元件应用于红外光学成像和光场聚焦，得到具有高性能、商业化的微系统原型器件

本项目面向红外波段在制导、成像等应用领域，针对满足苛刻环境下红外介电材料微光学元件的制备难题，提出了一种新型的飞秒激光复合技术对这一难题进行挑战。从原理、机制、设计到产品制备方面详细研究一种新型的飞秒激光纳米制造技术。研究红外材料的飞秒激光非线性作用机制与超快动力学过程，飞秒激光诱导微爆破的物理机制和烧蚀特性，飞秒激光表面刻蚀与表面再处理、内部折射率修复制备介电材料微纳结构以及不同偏振状态下的光学元件表面性能，红外微光学元件的成像、聚焦特性。揭示了飞秒激光与红外材料作用的非线性物理机制，微结构产生的演化机制；同时再介电材料上制备了二维类透镜、波带片、折衍混合结构，并实现了多波长成像以及湿法辅助粗糙度修复，发表SCI论文8篇，申请发明专利3项，协助培养了博士生1名，培养了硕士生2名。该项目成果为红外制导、成像、VR/AR等领域提供一种可实用化的微光学元件。