Thylén Lars, Qiu Min, Anand Srinivasan
Department of Microelectronics and Information Technology, Royal Institute of Technology (KTH), Electrum 229, 164 40 Kista (Sweden).
Chemphyschem. 2004 Sep 20;5(9):1268-83. doi: 10.1002/cphc.200301075.
The field of photonic crystals has, over the past few years, received dramatically increased attention. Photonic crystals are artificially engineered structures that exhibit a periodic variation in one, two, or three dimensions of the dielectric constant, with a period of the order of the pertinent light wavelength. Such structures in three dimensions should exhibit properties similar to solid-state electronic crystals, such as bandgaps, in other words wavelength regions where light cannot propagate in any direction. By introducing defects into the periodic arrangement, the photonic crystals exhibit properties analogous to those of solid-state crystals. The basic feature of a photonic bandgap was indeed experimentally demonstrated in the beginning of the 1990s, and sparked a large interest in, and in many ways revitalized, photonics research. There are several reasons for this attention. One is that photonic crystals, in their own right, offer a proliferation of challenging research tasks, involving a multitude of disciplines, such as electromagnetic theory, nanofabrication, semi-conductor technology, materials science, biotechnology, to name a few. Another reason is given by the somewhat more down-to-earth expectations that photonics crystals will create unique opportunities for novel devices and applications, and contribute to solving some of the issues that have plagued photonics such as large physical sizes, comparatively low functionality, and high costs. Herein, we will treat some basics of photonic crystal structures and discuss the state-of-the-art in fabrication as well give some examples of devices with unique properties, due to the use of photonic crystals. We will also point out some of the problems that still remain to be solved, and give a view on where photonic crystals currently stand.
在过去几年中，光子晶体领域受到了极大的关注。光子晶体是人工设计的结构，其介电常数在一维、二维或三维上呈现周期性变化，周期与相关光波长相当。这种三维结构应表现出与固态电子晶体类似的特性，如带隙，即光在任何方向都无法传播的波长区域。通过在周期性排列中引入缺陷，光子晶体表现出与固态晶体类似的特性。光子带隙的基本特征在20世纪90年代初确实得到了实验证明，并引发了对光子学研究的极大兴趣，并在许多方面使其重新焕发生机。受到关注有几个原因。一是光子晶体本身就带来了大量具有挑战性的研究任务，涉及电磁理论、纳米制造、半导体技术、材料科学、生物技术等众多学科。另一个原因是人们更实际的期望，即光子晶体将为新型器件和应用创造独特机会，并有助于解决困扰光子学的一些问题，如物理尺寸大、功能相对较低和成本高。在此，我们将探讨光子晶体结构的一些基础知识，讨论制造方面的最新进展，并给出一些由于使用光子晶体而具有独特性能的器件示例。我们还将指出一些仍有待解决的问题，并对光子晶体目前的状况发表看法。
