六通道光子晶体波分复用器的研究与设计

Research and Design of Six-Channel Photonic Crystal Wavelength Division Multiplexer

基于光子晶体谐振腔的耦合原理,采用环形腔与微腔结构结合的形式,设计了一种六通道波分复用器。利用平面波展开法研究了晶格常数为0.55μm时光子晶体禁带范围随介质柱半径的变化关系,并得到其能带结构。采用时域有限差分法分析了谐振腔结构对波长的影响,得到了该谐振腔结构的传输特性曲线及电场分布,并实现了波长为1.3298,1.4316,1.4419,1.5564,1.5966,1.6191μm的六通道波分复用。实验结果表明,该器件通过调节微腔内外的介质柱半径进行选频,通过增加反射点的微腔结构减少串扰,通过改变输出端边缘介质柱的半径提高输出效率。最终实现透射率大于90%,平均带宽为9 nm的通道,且通道间串扰小,窄带特性好。器件尺寸仅为13.4μm×17.6μm,有利于进行光器件集成,具有潜在的应用价值。

In the present paper,based on the coupling principle of photonic crystal resonator,a six-channel wavelength division multiplexer is designed by combining ring cavity with micro cavity structure.By using the plane wave expansion method,the relationship between the band gap of photonic crystal and the radius of dielectric cylinder is studied when the lattice constant is 0.55μm,and the band structure is obtained.The influence of the resonator structure on the wavelength is analyzed by using the finite difference time domain method.The transmission characteristic curve and electric field distribution of the resonator structure are obtained.Six-channel wavelength division multiplexing with wavelengths of 1.3298,1.4316,1.4419,1.5564,1.5966,1.6191μm is realized.Experimental results show that the device can select the frequency by adjusting the radius of the dielectric column inside and outside the microcavity,reduce the crosstalk by increasing the micro cavity structure of the reflection point,and improve the output efficiency by changing the radius of the dielectric column at the output edge.A channel with a transmittance of more than 90%and an average bandwidth of 9 nm is finally realized,and the crosstalk between channels is small and the narrow band characteristic is good.The size of the device is only 13.4μm×17.6μm,which is conducive to optical device integration and has potential application value.