二维正方晶格光控太赫兹波调制器

摘要

A novel terahertz modulator based on photonic crystal is presented. The modulator combines the structure of line defect and point defect,and is designed to be tunable by filling the point defect with nonlinear material GaAs. Without external pumplight, there is defect mode in the point defect. While by applying external pumplight to the defect with specific wavelength and intensity,the defect mode in the two defects soutwill disappears. Based on this mechanism,the device can modulates the on-off state of the terahertz wave in specific wavelength. The numerical simulation results show that this THz modulator has a extinction ratio of more than 51. 10 dB , responses within dozens of picoseconds,and has a small size and is easy to integrate.%提出了一种基于二维正方晶格光子晶体的光控太赫兹波调制器.该光子晶体调制器采用线缺陷和点缺陷组合的结构,通过在点缺陷处填充非线性介质砷化镓,使其成为光控可调谐光子晶体.当没有外加泵浦光时,点缺陷处存在缺陷模;当在缺陷处加一定光强和波长的光波时,缺陷处的缺陷模消失.基于这种机制,此器件可实现对某一波长的太赫兹波实现通、断调制.仿真结果表明:调制器的消光比大于51.10 dB,调制时间在几十皮秒,并且具有体积小、易于集成的优点.