基于三角晶格光子晶体多模波导1×2分束器的优化设计

Optimization design of a 1×2 Beam Splitter Based on Photonic Crystal Multimode Waveguide of Triangular Lattice PBG

依据自映像原理,设计了一种基于三角晶格光子晶体多模波导的1×2分束器。采用时域有限差分法模拟了光波在分束器中的传播行为,并计算了分束器的传输效率。结果表明,仅仅通过改变多模波导与输出波导联结处的介质柱的位置对结构进行优化,便可大大提高分束器在工作点频率处的传输效率和带宽,其多模耦合区的长度可低至3.1μm。因而本文所设计的分束器具有更小的器件尺寸和更高的传输效率,易于大规模集成的实现,在未来的集成光路中具有广泛的应用价值。

On the basis of self-imaging principle, a 1 ×2 beam splitter based on muhimode waveguide of triangular lattice PBG was designed. The finite-difference time-domain method is adopted to simulate the propagation of the optical wave in the beam splitter. And the output efficiency of the whole beam splitter was caltulated. The results show that the transmission efficiency and bandwidth at working point can be improved to large degree by adjusting the positions of the dielectric rod lying at the junctions between the multimode waveguides and output waveguides. Compared with that the beam splitter is based on muhimode waveguide of triangular lattice PBG with the same parameter, the beam splitter in this paper has much shorter size and higher output efficiency. It is easy to be integrated in optical circuit, and it has potential application in futurephotonic integrate circuits.