摘要
结合Mach-Zehnder干涉原理和多模干涉(MMI)耦合器的散射矩阵,从理论上推导出梯形干涉链可调谐光滤波器(LTOF)输出光场的表达式,采用优化算法搜索出不同级联级数下MMI耦合器的最佳分光比,并分析了衍射阶数和电极长度对LTOF调谐输出性能的制约关系。结果表明,对应最大峰值功率,存在随级联级数增加而增大的最佳分光比;增加级联级数会导致峰值功率和3 dB带宽减小,峰值隔离度增大;电极长度为原电极的1.4倍时,可实现LTOF连续双向宽调谐的功能。通过比较,验证了理论模型及分析方法的正确性。
Based on the interference principle of Mach-Zehnder interferometer and the transfer matrix of multimode interference （MMI） coupler, the expression of the optical field at the output port was derived and the performance of the ladder-interference-type structure based tunable optical filter （LTOF） was investigated. The results show that there is an optimum splitting ratio of the MMI coupler for different stages obtained by algorithm. The increment in number of ladders for the LTOF will lead to the reducting peak power and narrowing 3 dB bandwidth. According to the effect of the diffraction order and the length of electrodes on the tuning performance, it is proposed to prolong the length of electrode by 40% to realize the continuous tuning. An example is given to verify the availability of this method.
出处
《光学精密工程》
EI
CAS
CSCD
北大核心
2005年第6期627-632,共6页
Optics and Precision Engineering
基金
国家自然科学基金(No.1017405790201011)
教育部科学技术研究重点项目(No.105148)
四川省应用基础科学研究计划(No.03JY029-048-1)
高等学校博士学科点专项科研基金资助项目
关键词
导波光学
可调谐光滤波器
梯形干涉链结构
分光比
连续调谐
guided wave optics
tunable optical filter
ladder-interference-type structure
splitting ratio
continuous tuning
