基于亚波长表面结构的宽带高效成像方法和实验研究

Imaging is an important part of modern optics area. As the progress of precise optical manufacture and testing technology, optical imaging area expresses a significant development trend towards integration, lightweight and large aperture. However, based on the geometrical optics, traditional imaging principle has to rely on the surface shape and materials, leading to the lower design freedom and heavy structure. Subwavelength structures have represented a remarkable potential to solve these problems. Many researchers designed focusing, imaging and deflecting devices with planar and lightweight features. But limited by the phase manipulating theory, there are many scientific problems such as narrow bandwidth and low efficiency. In our project, we present research the broad bandwidth property of subwavelength structures to obtain high efficiency imaging devices design methods. Using this way, the efficiency can be raise to 90%. The results will break the limited of traditional theory, and establish the basis of the new imaging technology applied in integrating optical chip, telescope, imager, and so on.

成像是现代光学的重要组成部分，随着精密光学加工和检测技术进步，光学成像领域表现出向集成化、轻量化、超大口径等方向发展的趋势。然而建立在几何光学Snell折射定律基础上的折射和反射成像原理，依赖于界面形状和材料，导致光学元件设计自由度低、体积重量大，越来越难以满足光学成像技术的长远发展。亚波长结构的出现为解决传统技术困境提供了契机，许多学者研究获得了具有平面轻量化特性的亚波长结构聚焦、成像和偏折器件，但受限于位相调控理论的不完善以及设计方法局限，仍然存在带宽窄、效率低等诸多科学问题。本项目在前期研究基础上，提出进一步深入研究亚波长表面结构的宽带调制特性，获得宽带、高效亚波长表面结构成像器件设计方法，将效率提高到90%以上，并开展宽带复合消色差机理和成像实验研究。研究成果有望打破传统Snell折射定律的理论限制，为新型光学成像技术在集成光芯片、望远、便携成像等领域的应用奠定重要理论基础。

本项目围绕新一代轻量化成像技术发展需求，深入开展了亚波长表面结构对光波的宽波段位相调制机理研究，掌握了亚波长表面结构高效率位相调制方法，阐明了手性排布矩形结构、悬链线结构等亚波长表面结构的高效位相调制规律和设计方法，设计出在8.5-11.2μm波长范围内能量利用率大于95%的亚波长结构器件；建立了基于亚波长表面结构的高效率、宽带光学成像器件优化设计方法，设计出多波长聚焦微透镜阵列并完成聚焦性能测试；建立了亚波长表面结构复合消色差原理方法和数理模型，实现426nm～638nm可见光范围消色差系统设计，通过搭建测试平台完成星点与分辨率靶成像测试，验证了复合消色差模型的正确性。项目成果有望为新型光学成像技术在集成光芯片、望远、便携成像等领域的应用奠定重要理论基础。