Chow E, Lin S Y, Johnson S G, Villeneuve P R, Joannopoulos J D, Wendt J R, Vawter G A, Zubrzycki W, Hou H, Alleman A
Sandia National Laboratories, Albuquerque, New Mexico 87185, USA.
Nature. 2000 Oct 26;407(6807):983-6. doi: 10.1038/35039583.
Optoelectronic devices are increasingly important in communication and information technology. To achieve the necessary manipulation of light (which carries information in optoelectronic devices), considerable efforts are directed at the development of photonic crystals--periodic dielectric materials that have so-called photonic bandgaps, which prohibit the propagation of photons having energies within the bandgap region. Straightforward application of the bandgap concept is generally thought to require three-dimensional (3D) photonic crystals; their two-dimensional (2D) counterparts confine light in the crystal plane, but not in the perpendicular z direction, which inevitably leads to diffraction losses. Nonetheless, 2D photonic crystals still attract interest because they are potentially more amenable to fabrication by existing techniques and diffraction losses need not seriously impair utility. Here we report the fabrication of a waveguide-coupled photonic crystal slab (essentially a free-standing 2D photonic crystal) with a strong 2D bandgap at wavelengths of about 1.5 microm, yet which is capable of fully controlling light in all three dimensions. These features confirm theoretical calculations on the possibility of achieving 3D light control using 2D bandgaps, with index guiding providing control in the third dimension, and raise the prospect of being able to realize unusual photonic-crystal devices, such as thresholdless lasers.
光电器件在通信和信息技术中越来越重要。为了实现对光（在光电器件中承载信息）的必要操控，人们在光子晶体的开发方面投入了大量精力——光子晶体是一种周期性介电材料，具有所谓的光子带隙，能阻止带隙区域内具有特定能量的光子传播。一般认为，带隙概念的直接应用需要三维（3D）光子晶体；其二维（2D）对应物将光限制在晶体平面内，但在垂直的z方向上则不然，这不可避免地会导致衍射损耗。尽管如此，二维光子晶体仍然备受关注，因为它们可能更易于采用现有技术制造，而且衍射损耗不一定会严重影响其用途。在此，我们报告了一种波导耦合光子晶体平板（本质上是一种独立的二维光子晶体）的制造方法，该平板在波长约为1.5微米处具有很强的二维带隙，并且能够在所有三个维度上完全控制光。这些特性证实了关于利用二维带隙实现三维光控制可能性的理论计算，其中折射率引导在第三维度上提供控制，并提高了能够实现诸如无阈值激光器等特殊光子晶体器件的前景。
