掺杂石墨烯系统电场调控的非线性太赫兹光学特性研究

摘要

In this paper, we present a detailed theoretical study of nonlinear terahertz optical properties of graphene in the presence of electric field and terahertz radiation field. The optical current is computed and investigated on the basis of quantum theory and semi-classical Boltzmann equations. It shows a large nonlinear terahertz response and the nonlinearity becomes larger with increasing electric field or decreasing terahertz frequencies. Moreover, it is found that the optical nonlinearity can be modified and controlled by electric fields.%石墨烯是单原子厚的二维狄拉克相对论费米子系统，其优秀的光电学性质得到了广泛的关注和研究。本论文利用量子理论研究掺杂石墨烯系统外电场和光场共同作用下的非平衡载流子的非线性太赫兹光学性质。研究发现，掺杂石墨烯带内光吸收表现出强的非线性太赫兹光学特性。随着外加偏压电场的增大，石墨烯非线性光学响应增强；随着外界太赫兹光频率的减小，非线特性增强。研究表明通过改变电场强度，可以有效调节石墨烯系统太赫兹非线性光学特性。研究结果为探索和发展以石墨烯为基础的新型纳米太赫兹光电器件的研究和实际应用提供了理论依据。