Self-focusing lens in Sun-flower graded photonic crystal
-
摘要: 大多数渐变光子晶体渐变透镜都是以正方晶格或三角晶格排布为基础,并且多选择硅或二氧化硅等高折射率材料,研究的波段多为红外波段。随着可见光通信技术的发展,在可见光波段研究低折射率材料的自聚焦透镜变得很有意义。为了迎合这种需求,提出了Sun-flower型渐变光子晶体自聚焦透镜。首先,通过比较TE和TM两种偏振模式Sun-flower渐变光子晶体朗伯透镜在可见光波段的会聚强度,发现TM型的会聚效果远远优于TE型。然后,以TM型Sun-flower渐变光子晶体为基础设计圆柱形自聚焦平板透镜,通过光场传输的模拟计算给出平板透镜在可见光波段自聚焦的拍长,进一步优化平板透镜会聚光强设计透镜的层数,结果表明在层数为22时效果最佳。最后,讨论了列数的减少对平板透镜的影响,结果表明随着列数的减少光强减弱。这对于制作出高性能会聚效果、短焦距、小体积的光学集成器件有重要的指导意义。
-
关键词:
- 自聚焦透镜 /
- Sun-flower /
- 渐变光子晶体 /
- 朗伯透镜 /
- 平板透镜
Abstract: Most photonic crystal lens based on square or triangular lattice usually uses high refractive index materials such as Si or SiO2. And the study on such lens has been focused on the infrared wavelength range. With the development of the visible light communication technology, the research of Sun-flower self-focusing lens with low refractive index materials in visible band becomes very meaningful. To meet that requirements, self-focusing lens based on Sun-flower shaped graded PC was proposed. Firstly, by comparing the convergence intensity of this proposed lens between TE-polarized and TM-polarized mode, the convergence effect of TM polarization was superior to the convergence effect of TE polarization. Then self-focusing flat lens based on TM mode Sun-flower graded PC was designed. The beat length of the flat lens was given by the simulation of optical field transmission. The layers of the flat lens were optimized, and the best number of the layers was 22. In the end, the influence of the number of columns was discussed. The results show that the intensity decreases as the number of columns reduces. It has great guiding significance to make optical integrated devices with high-performance convergence effect, short focal length and small volume.-
Key words:
- self-focusing lens /
- Sun-flower /
- graded photonic crystals /
- luneburg lens /
- flat lens
-
[1] Lee P T, Lu T W, Fan J H, et al. High quality factor microcavity lasers realized by circular photonic crystal with isotropic photonic band gap effect[J]. Applied Physics Letters, 2007, 90(15):151125. [2] Zhang X, Sun X, Tang H X. A 1.16-m-radius disk cavity in a sunflower-type circular photonic crystal with ultrahigh quality factor[J]. Optics Letters, 2012, 37(15):3195-3197. [3] Bhattacharjee J, Siraji A A, Alain M S. Phase modulated circles in a sunflower-type circular photonic crystal with ultra-small mode area and high-Q cavity[C]//Electrical Engineering and Information Communication Technology (ICEEICT), 2014 International Conference on IEEE, 2014:6919038. [4] Pan Jihuan, Su An, Meng Chengju. Modulation of medium refractive index on filter performance of photonic crystal quantum well[J]. Infrared and laser Engineering, 2014, 43(3):833-837. (in Chinese) [5] Li Wensheng, Zhang Qin, Huang Haiming, et al. Polarization properties of Tamm state of one-dimensional photonic crystal containing single-negative materials[J]. Infrared and Laser Engineering, 2014, 43(5):1600-1604. (in Chinese) [6] Yuan Wei, Zhang Jianqi, Qin Yuwei, et al. Near-infrared spectral region photonic crystal band gaps and KTP defect[J]. Infrared and Laser Engineering, 2016, 45(1):0104005. (in Chinese) [7] Smith D R, Mock J J, Starr A F, et al. Gradient index metamaterials[J]. Phys Rev E, 2005, 71(3Pt2B):036609. [8] Howard J W, Ryan-Howard D P. Optical design of thermal imaging systems utilizing gradient-index optical materials[J]. Optical Engineering, 1985, 24(2):242263. [9] Wang Chi, Xu Tingting, Bi Shubo, et al. Curve-fitting algorithm of measuring focusing constant of gradient-index fiber lens[J]. Optics and Precision Engineering, 2015, 23(12):3309-3315. (in Chinese) [10] Wu Q, Gibbons J M, Park W. Graded negative index lens by photonic crystals[J]. Optics Express, 2008, 16(21):16941-16949. [11] Centeno E, Cassagne D. Graded photonic crystals[J]. Optics Letters, 2005, 30(17):2278-2280. [12] Xiao S, Qiu M. Study of transmission properties for waveguide bends by use of a circular photonic crystal[J]. Physics Letters A, 2005, 340(5):474-479. [13] Sun X H, Wu Y L, Liu W, et al. Luneburg lens composed of sunflower-type graded photonic crystals[J]. Optics Communications, 2014, 315(6):367-373. [14] Hrennikoff A. Solution of problems of elasticity by the framework method[J]. Journal of Applied Mechanics, 1941, 8(4):169-175. [15] Liu W, Sun X, Gao M, et al. Luneburg and flat lens based on graded photonic crystal[J]. Optics Communications, 2016, 364(4):225-232.
计量
- 文章访问数: 553
- HTML全文浏览量: 97
- PDF下载量: 110
- 被引次数: 0