宽波段波状多层膜结构偏振分束器的设计与优化  

Design and optimization of broadband polarization beam splitter made from a wave-structured multilayer film

作　　者：彭皓[1] 沈伟东[1] 杨陈楹[1] 章岳光[1] 刘旭[1] 

机构地区：[1]浙江大学光电信息工程学系,现代光学仪器国家重点实验室,杭州310027

出　　处：《物理学报》2014年第13期203-208,共6页Acta Physica Sinica

基　　金：国家高技术研究发展计划(批准号:2012AA040401);国家自然科学基金(批准号:61275161);中央高校基本科研业务专项资金(批准号:2014FZA5004);浙江省自然科学基金(批准号:LY13F050001)资助的课题~~

摘　　要：本文基于二维光子晶体波状多层膜结构,提出了叠加两种不同膜厚的周期膜堆来拓宽偏振分束器有效带宽的方法.采用粒子群优化算法,建立偏振分束特性的评价函数,优化结构和薄膜厚度等参数,获得了中心波长565 nm,带宽220 nm,平均消光比大于30 dB的宽波段偏振分束器.采用时域有限差分方法分析了膜层顶角的角度敏感性和波状结构的电场分布.结果表明,两个周期膜堆组合的结构解决了禁带不连续的情况,而粒子群优化算法的使用加快了结果收敛,有效地扩展了偏振分束带宽.Based on the 2D-PC wave multilayer film structure, a method to broaden the bandwidth of polarization beam splitter is proposed, which is composed of two different thickness periodic film stacks. Combined with the evaluation function of polarization splitting characteristic, the particle swarm optimization method is employed to design the optimal structural parameters. A broadband and compact polarization beam splitter is acquired, in which the center wavelength is 565 nm and its working range has achieved 220 nm with the average extinction ratio over 30 dB. In addition, by using the finite difference time domain method, the band structure and transmission spectrum of the wave-structure multilayer film are calculated, the angle sensitivity of the structure is investigated in detail. And we also study the electromagnetic field in the wavy-structure. Simulation results prove that the structure composed of the two different thickness periodic film stacks can avoid the discontinuity of bandgap, and PSO method can accelerate the convergence of the optimization algorithm and extend the bandwidth effectively.

关 键 词：偏振分束器 光子晶体 光学薄膜 粒子群优化算法 

分 类 号：O436.3[机械工程—光学工程]