Park Jeong-Ho, Choi Won San, Koo Hye Young, Hong Jae-Chul, Kim Dong-Yu
Center for Frontier Materials, Department of Materials Science and Engineering, Gwangju Institute of Science and Technology, Buk-Gu, Gwangju 500-712, South Korea.
Langmuir. 2006 Jan 3;22(1):94-100. doi: 10.1021/la052071n.
A three-dimensionally ordered array of close-packed colloidal spheres, a photonic crystal structure in which the refractive index of the medium interstitial lattice in a colloidal crystal spatially changes in the [111] crystallographic axis, is demonstrated. The colloidal photonic crystal structure with refractive index chirping was produced by infiltration of a monomer and organic dopants with a high refractive index into a silica opal, followed by interfacial gel polymerization. The resulting photonic crystal structure has a gradually varying stop band at each different (111) plane in the face-centered cubic (fcc) crystal structure at a normal incidence. This novel structure exhibited optical characteristics that have band-gap broadening by the superposition of stop bands at each plane of the crystal with different dielectric functions. Moreover, the refractive index perturbation in the [111] fcc opal also showed a defect state within a pseudo-photonic band gap. This new type of photonic crystal structure should be useful for the band-gap engineering of photonic-band-gap materials.
展示了一种由紧密堆积的胶体球组成的三维有序阵列，这是一种光子晶体结构，其中胶体晶体中介质间隙晶格的折射率在[111]晶轴方向上发生空间变化。通过将单体和高折射率有机掺杂剂渗透到二氧化硅蛋白石中，随后进行界面凝胶聚合，制备出了具有折射率啁啾的胶体光子晶体结构。所得的光子晶体结构在面心立方（fcc）晶体结构的每个不同（111）平面处，在正入射时具有逐渐变化的禁带。这种新颖的结构展现出光学特性，即通过在具有不同介电函数的晶体各平面处的禁带叠加实现带隙展宽。此外，[111] fcc蛋白石中的折射率微扰在伪光子带隙内也显示出缺陷态。这种新型的光子晶体结构对于光子带隙材料的带隙工程应是有用的。
