定向耦合光子晶体偏振光分束器的设计

Design of Photonic Crystal Polarizing Beam Spliter Based on Directional Coupling

在只有TE模光子带隙空气孔三角晶格光子晶体研究的基础上,设计出一种全新的、结构紧凑的定向耦合光子晶体偏振光分束器。根据波导间相互耦合与自映像原理,采用时域有限差分法分析了该器件的光传输特性。研究结果表明:由于导光机制不同,TE模和TM模可通过不同的相干长度分离;两种偏振光在波长1.55μm附近透射率都达到95%以上;该器件的尺寸比传统偏振光分束器短。这些优异性能在光子晶体集成电路中有极大的应用价值。

Designed is a novel and compact photonic crystal polarizing beam splitter based on directional coupling with a triangular lattice of air holes, which only exhibit photonic band gaps for transverse-electric（TE） modes. The optical propagation properties of the device have been demonstrated by finite difference time domain method according to the waveguides directional coupling and self-imaging principle. The results show that due to different guiding mechanisms, TE and TM light can be separated owing to strikingly different beat lengths; the two polarizations transmission rate will be up to 95% in the vicinity of λ=1.55 μm and the size of the device can be much shorter compared with the conventional polarizing beam splitter. These excellent properties Will be widly applied in photonic integrate circuits（PCI）.