中国激光, 2015, 42 (12): 1205001, 网络出版: 2015-12-11
硫系60°弯曲光子晶体波导结构优化及传输特性研究
Transmission Characteristics and Structure Optimization of 60° Bent Chalcogenide Photonic Crystal Waveguides
集成光学 硫系玻璃 光子晶体波导 传输效率 带宽 integrated optics chalcogenide glass photonic crystal waveguides transmission efficiency bandwidth
摘要
通过平面波展开法(PWE)计算硫系光子晶体带隙并采用时域有限差分法(FDTD)模拟硫系60°弯曲光子晶体波导的传输特性,在波导弯曲部分线缺陷处添加小空气孔缺陷,提高了其带宽和透光性。在60°弯曲区域线缺陷外边缘处引入2个对称空气孔,通过改变其半径来改善波导传输效率。模拟结果表明,当引入半径为0.54R 的空气孔时,传输带宽由初始的60 nm 提高到161 nm,但此时透射率波动性较大。在此基础上在弯曲线缺陷中心处又引入若干个空气孔,当引入3个半径为0.48R 的空气孔时,此种结构不但提高了波导的传输效率,并且使传输带宽增加到340 nm。将单个60°弯曲波导优化结构应用于连续60°弯曲波导中,研究结果表明连续弯曲波导的传输效率得到显著提高。
Abstract
The plane wave expansion method (PWE) is adopted to calculate chalcogenide photonic crystal bandgap, and finite difference time domain (FDTD) method is used to simulate transmission characteristics for 60° bent chalcogenide photonic crystal waveguide. Two symmetric air-holes are introduced in outer edge of line defects in the 60° bent region, in order to improve the transmission efficiency by adjusting the radii of the air-holes. The simulation result shows that transmission bandwidth is widened from the initial 60 nm to 161 nm while the radius of the air-holes is 0.54R, however, the transmission efficiency fluctuates violently. Then some more air-holes are introduced in the central line defect in bent region. It is noticed that when 3 air-holes with radius of 0.48R are added, not only the transmission efficiency is improvement, but also the transmission bandwidth is widened to 340 nm. Continuous bend of 60° waveguide structure optimization is similar to that of single one, and the result shows that the transmission efficiency in continuous bend of waveguide can be significantly improved.
魏凤娟, 张巍, 韩金涛, 王贤旺, 吴越豪, 张培晴, 戴世勋, 聂秋华. 硫系60°弯曲光子晶体波导结构优化及传输特性研究[J]. 中国激光, 2015, 42(12): 1205001. Wei Fengjuan, Zhang Wei, Han Jintao, Wang Xianwang, Wu Yuehao, Zhang Peiqing, Dai Shixun, Nie Qiuhua. Transmission Characteristics and Structure Optimization of 60° Bent Chalcogenide Photonic Crystal Waveguides[J]. Chinese Journal of Lasers, 2015, 42(12): 1205001.