嵌入式三色光变器设计  

Design of an embedded tricolor-shifting device

作　　者：徐平[1] 唐少拓 袁霞[1] 黄海漩[1] 杨拓[1] 罗统政 喻珺[1] 

机构地区：[1]深圳大学电子科学与技术学院,微纳光电子技术研究所,深圳518060

出　　处：《物理学报》2018年第2期99-109,共11页Acta Physica Sinica

基　　金：国家自然科学基金(批准号：61275167); 深圳市基础研究计划(批准号：JCYJ20140418095735591,JCYJ20130329103020637,JC200903120023A)资助的课题~~

摘　　要：为解决目前亚波长二元矩形结构在光学防伪应用方面存在的防伪性能有待提升、制作困难导致性能劣化等问题,提出正弦结构等效矩形结构实现基于嵌入式亚波长一维单周期正弦结构的三色光变器.模拟仿真表明,亚波长正弦结构与原亚波长矩形结构性能相似,可获得优越的三色变换功能.当自然光以45°角入射时,可在方位角0°,58°,90°分别获得相应的蓝光、绿光、红光三色反射峰,反射率分别达到90%,89%,100%.分析并提出了该器件周期、槽深、膜厚以及入射角变化对反射峰的影响规律,探索了运用无掩模的双光束干涉曝光法制作母版的实验过程.提出的正弦结构三色光变器实现了方位角调节的高衍射效率自然光三色光变效果,突破了目前两色光变防伪的局限,同时降低了制作难度,可用通用的全息生产技术制作光栅结构,在光变图像防伪领域有重要应用.Insufficient anti-counterfeiting performance and difficulties in manufacturing lead to performance degradation of the subwavelength rectangular structure grating, when it is applied to the field of optical anti-counterfeiting. To solve the problem, an embedded subwavelength one-dimensional simple periodic sinusoidal grating structure is proposed in this paper to replace the previous structure with a rectangular structure. By using equivalent medium theory, we find that the rectangular structure whose duty ration is 0.5 has the same effective refractive index as the sinusoidal structure. Then equivalent structure parameters of a sinusoidal structure are obtained based on a rectangular structure tricolor-shifting device, and the characteristics of the reflection peak are analyzed. The result shows that the sinusoidal structure gating can realize the same tricolor-shifting properties with a higher reflective efficiency as the rectangular structure gating.When the incidence angle of natural light is 45° for TE and TM polarization, the highest reflectivity values of 90%,89% and 100% in blue, green and red bands can be obtained at the azimuths of 24°, 63° and 90°, respectively. Then the azimuth-induced color shifts of blue, green and red are realized. Physical mechanism of the equivalent rectangular structure to sinusoidal structure is explained in non-resonance and resonance conditions. Under the non-resonance condition, both of them can be regarded as a layer of completely equivalent optical film, possessing exactly the same optical properties. Under the resonance condition, they can be regarded as a slab waveguide. So when their effective refractive indexes, periods, film thicknesses and depths are equal, they have the same optical characteristic matrixes,supported guided modes, and resonant peak positions. In addition, we investigate the influences of the deviations of key parameters, including grating period, grating depth, coating film thickness, and incidence angle, and propose the rigorous redundancy of the

关 键 词：亚波长 正弦结构 三色光变换 双光束干涉曝光 

分 类 号：TH74[机械工程—光学工程]