Interaction between radiation field and matter in a photonic crystal

1. 光子晶体的发展：我们成功地开发了1)二维（2D）空气棒型光子晶体、2)二维平板（准3D）光子晶体和3)三维（2D）有序球体光子晶体，并揭示了它们的光学性质。分别采用毛细管法制备阵列光纤，采用最先进的AlGaAs芯层介质波导微加工技术，采用聚苯乙烯粒子的辐射压力和自组织技术，按此顺序制备。结果，我们发现1)的PC是第一个在近红外波段具有带隙的PC。根据2)，我们首次确定了PC板的引导模式并验证了带隙的存在。我们还制作了带有线缺陷的pc，并通过实验确定了缺陷或局部模式。光与PC的相互作用：1)利用亚皮秒光脉冲的飞行时间，我们发现群速度vg随着带边缘的接近而减小，并观测到vg值小至0.05倍c（真空中光速）。2)我们首次在2D PC上观察到激光作用。这一现象被解释为由一个小的vg引起的，这使得光与物质之间的有效相互作用长度足够长。3)我们通过实验证明，在不同波长的PC中，由于其独特的波段色散，或者借助Umclapp过程，我们很容易满足所谓的相位匹配。4)我们通过开发一种新的功能强大的光谱仪，揭示了缺少一排气孔的基于pc板的波导显示出独特的光学特性。也就是说，我们明确地确定了各种设计和制造的组件的缺陷或局部模式，例如突然弯曲的组件，y分路器和定向耦合器，并测量了这些组件的传播损耗。为未来通信应用的超高速平面光集成电路的开发奠定了坚实的基础。少

1. Development of photonic crystals (PCs) : We successfully developed 1) two-dimensional (2D) air-rods type PCs, 2) 2D slab (quasi- 3D) type of PCs, and 3) three- dimensional (2D) PC of ordered spheres, and revealed their optical properties. Those were fabricated in this order by using the capillary method for arrayed fibers, the state-of- arts micro-machining technique for the dielectric waveguide with AlGaAs core-layer, and radiation pressure and self-organization of polystyrene particles, respectively. As a result, we find that the PC of 1) is the first one developed with a band gap at near-infrared wavelengths. Ass for 2), we have for the first time identified the guided modes and verified the existence of the band gap for PC slabs. We also fabricated PCs with line defect and identified experimentally the defect or local modes.2. Interaction between light and PC : 1) Using time-of-flight of sub-picosecond light pulse we find that the group-velocity vg is smaller as the band edge is … More approached, and have observed a vg-value as small as 0.05 times c (light velocity in vacuum). 2) We observed for the first time laser action in a 2D PC. This phenomenon is interpreted as arising from a small vg, which makes the effective interaction length between light and matter long enough. 3) We experimentally demonstrated that the so-called phase- matching is easily satisfied at various wavelengths in a PC, either due to its unique band dispersion, or with help of Umclapp process. 4) We have revealed, by developing newly a powerful spectrometer, that PC-slab-based waveguides with a line of air-holes missing show distinguished optical properties. Namely, we identified unambiguously the defect or local modes for a variety of components designed and fabricated, such as abruptly-bent ones, Y-splitter, and directional coupler, and also measured propagation loss of those. As a result, we have provided a firm basis for developing ultra-fast, planar light integrated circuit for future telecommunication use. Less