四通道二维光子晶体解波分复用系统

利用光子晶体环形腔缺陷模与线缺陷波导之间的共振耦合原理,设计了一种由主波导、环形腔和60°弯波导组成的四通道二维三角晶格光子晶体解波分复用系统。通过平面波展开法计算线缺陷波导的能带结构;利用时域有限差分法(FTDT)计算了不同频率的光波在该系统中的传输特性。最后,分析了影响输出效率和品质因子的因素并对该系统进行了改进。分析表明:改变环形腔内介质柱的半径可调节谐振频率,而在主波导末端增加反射介质柱以及改变耦合区域中介质柱的形状可提高各通道的谐振频率光波的透射率。计算结果显示:该系统较好地实现了4个波长的解波分复用,透射率均达90%以上。另外,该系统结构简单,便于加工制造,且体积小,有利于大规模集成。

Four-channel WDM system based on two-dimensional photonic crystal

Based on the resonant coupling principle between the defect mode of a ring resonator and the line-defect waveguide, a four-channel Wavelength Division Multiplexing (WDM) system was designed by using the 2D triangular lattice photonic crystal. This system was composed of a line-defect waveguide, ring resonators and 60° bend waveguides. The band structure of the line waveguide was investigated by the plane-wave expansion method. The transmission characteristics of light wave with different frequencies in the system were simulated by the finite difference time domain method, the effects of factors on output efficiency and quality factor were analyzed and the system was improved. The analysis shows that the resonance frequencies depend on the radius of the dielectric rods. It is demonstrated that the transmission efficiencies of the system is improved greatly by changing the shapes of dielectric rods in the coupling region and adding the reflection dielectric rods at the end of bus waveguide. The numerical results indicate that the system has the ability to achieve the WDM for different wavelengths, and the transmission efficiencies of all the resonance wavelengths are still above 90%. The system is a simple structure and easy to be fabricated and processed. Moreorer, it has a smaller size, and could be large-scale integration.