空气孔硅光子晶体偏振无关3 dB分光器

提出并成功设计了基于自准直马赫-曾德尔干涉仪(SMZI)的空气孔硅光子晶体偏振无关3dB分光器。介绍了采用偏振透射谱匹配的方法,SMZI可以实现偏振无关分束的基础理论。通过连续改变SMZI两臂的光程差,基于匹配两个偏振的透射谱,成功实现了在归一化频率下将TE偏振和TM偏振的入射自准直光束进行1∶1分光。最后,利用时域有限差分数值模拟软件计算出来的TE偏振瞬时磁场分布图和TM偏振瞬时电场分布图验证了自准直光束的分光情况。结果显示:如果将工作波长定在1 550nm,该偏振无关3dB分光器大小仅为16.7μm×16.7μm。由于具有尺寸微小、结构简单并使用单一硅材料等特性,该分光器有望应用于集成光路中。

Polarization-independent 3 dB beam splitter in hole-type silicon photonic crystal

A Polarization-independent 3 dB Beam Splitter(PIBS) based on a self-collimation Mach-Zehnder Interferometer(SMZI) in a hole-type silicon photonic crystal(PhC) is proposed and successfully designed. According to theoretical analysis, it shows that the SMZI can implement the polarization-independent beam splitting by utilizing polarization transmission matching method. Then, by changing the path length difference of the SMZI continuously, the same splitting ratio 1:1 of self-collimation beams for both transverse-electric(TE) modes and transverse-magnetic(TM) modes is obtained at the operating frequency of 0.1774c/a based on matching two polarization transmission spectra. This behavior of the PIBS is also numerically demonstrated with the magnetic-field distribution for TE polarization and the electric-field distribution for TM polarization calculated by the time domain finite difference numerical simulation software. The results show that the dimension of the 3 dB PIBS is only 16.7μm×16.7μm when its working wavelength is at 1550 nm. With its small dimensions, simple structure and single silicon material, this 3dB PIBS may have practical applications in future photonic integrated circuits.