Dong G Y, Zhou J, Yang X L, Cai L Z
Department of Materials Science and Engineering, Tsinghua University, Beijing, 100084, China.
Opt Express. 2011 Jun 20;19(13):12119-24. doi: 10.1364/OE.19.012119.
We present a dual-negative refraction effect based on the overlapping bands in a two-dimensional triangular photonic crystal formed by holographic lithography. Under certain conditions, one incident plane wave launched into this photonic crystal can be dispersed into two negative refracted waves at the same frequency and the same perpendicular polarization state with different phase velocities and group velocities. We find that this dual-negative refraction behavior can be easily manipulated by adjusting the incident angle, the frequency of incident wave and the filling ratio of the PhC. This special effect can be applied to realize wave-front division and optical interference in optical holography. Based on this effect, a double focusing imaging phenomenon has been achieved by the PhC slab. These unique features may show great impacts on both fundamental physics and optical device applications.
我们展示了一种基于全息光刻形成的二维三角形光子晶体中重叠能带的双负折射效应。在特定条件下，入射到该光子晶体中的一个平面波可以在相同频率和相同垂直偏振态下被色散成两个具有不同相速度和群速度的负折射波。我们发现，通过调整入射角、入射波频率和光子晶体的填充率，可以很容易地控制这种双负折射行为。这种特殊效应可应用于光学全息术中实现波前分割和光学干涉。基于这种效应，光子晶体平板实现了双聚焦成像现象。这些独特特性可能会对基础物理学和光学器件应用都产生重大影响。
