Fig. 1. Diffraction theoretical model under the broadband light source illumination. The broadband light source is a white LED, and the microstructure array is the RPG.宽带光源微光学元件衍射理论模型图(宽带光源为白光LED, 微光学元件为矩形位相光栅)

Fig. 2. Relative light intensity distributions of zero, positive and negative one order of diffraction beams of three primary colors, where the RPG period d and the cone angle of incident beam θ of (a)−(e) are (7.5°, 4 μm), (7.5°, 8 μm), (7.5°, 40 μm), (14.5°, 4 μm) and (102.5°, 4 μm) respectively. The red, green, blue line represents the red, green, blue light of three primary colors respectively. The zero, positive and negative one order beam is represented by the thick horizontal, vertical short and thin horizontal line respectively. 零级、± 1级三衍射级次的相对光强分布　(a)−(e)入射光束锥角θ和光栅周期d分别分别为(7.5°, 4 μm), (7.5°, 8 μm), (7.5°, 40 μm), (14.5°, 4 μm), (102.5°, 4 μm); 图中红色、绿色、蓝色线分别代表三原色的红光、绿光、蓝光; 零级、+1级、–1级分别用粗横线、竖短线、细横线表示

Fig. 3. Relevant parameters of the dispersion parameter C. Where the red, black line respectively represents the red, zero order light beam. 色散量C的相关定参量示意图, 其中红线、黑线分别代表红色光束、零级光束

Fig. 4. Influences of grating period d and incident light cone angle θ on the dispersion parameter C. (a), (b) is the calculated relationship curve between C and d, or θ respectively, where the red circles represent the zero-dispersion boundary points. 色散量C与矩形位相光栅周期d, LED入射光束锥角θ的关系　(a)矩形位相光栅周期d; (b) LED入射光束锥角θ; 其中红圆圈表示零色散的边界点

Fig. 5. Structural testing diagrams of the RPG sample:　(a) After being developed; (b) the structural testing diagrams of the final sample after UV stamping.矩形光栅样品的结构测试图　(a)光刻显影后; (b)紫外线压印后

Fig. 6. Observation diagram of the diffraction beam:　(a) At zero-dispersion boundary point (θ = 34.71°, d = 4 µm); (b) θ = 3.58°, d = 4 µm. 实验光束观测图　(a)零色散边界点(θ = 34.71°, d = 4 µm); (b) θ = 3.58°, d = 4 µm

Fig. 7. Contrast curves of the relationship between the test and theoretical value of C with θ. 色散量C的理论值和测试值与入射光束锥角θ关系曲线的对比