光学仪器, 2017, 39 (4): 66, 网络出版: 2017-10-30
高偏振消光比铌酸锂波导调制器光路设计
Optical path design of LiNbO3 modulator with high polarization extinction ratio
光波导技术 LiNbO3波导相位调制器 偏振消光比 同基集成 optical waveguide technology LiNbO3 waveguide phase modulator polarization extinction ratio integration with group
摘要
设计了一种新的光路结构,用于提高LiNbO3波导相位调制器的偏振消光比。光路特点是,在质子交换波导3 dB功分器的输入端同基构造了TiLiNbO3波导模式分离定向耦合的结构以实现TE导模与TM模分离,Y分支波导位置下沉以避免前向TM辐射模的窜扰。效果表现为,与保偏光纤端耦合寄生的TM辐射模得到了有效抑制,寄生的TM导模被定向疏散。1 550 nm波长的BPM仿真运行表明,设计光路的偏振消光比达到87 dB以上。
Abstract
A new optical structure is designed to improve the polarization extinction ratio of LiNbO3 waveguide phase modulator.At the input of the 3 dB power divider of the proton exchange waveguide,there is a Ti-LiNbO3 waveguide mode separation directional coupler with the base structure for the separation of TE mode and TM mode.Y-branch waveguide is sunk to avoid scrambling of the forward TM radiation mode.The parasitic TM radiation mode with polarization-maintaining fiber is effectively suppressed and the parasitic TM guided mode is evacuated.The BPM simulation of 1 550 nm wavelength shows that the polarization extinction ratio of the designed optical path is more than 87 dB.
张威, 陈抱雪. 高偏振消光比铌酸锂波导调制器光路设计[J]. 光学仪器, 2017, 39(4): 66. ZHANG Wei, CHEN Baoxue. Optical path design of LiNbO3 modulator with high polarization extinction ratio[J]. Optical Instruments, 2017, 39(4): 66.