中文摘要：

采用紧束缚模型分别描述单层、双层石墨烯的能带结构，利用光子．电子相互作用的二阶微扰理论分别计算单光子和双光子吸收系数．计算结果表明：单层石墨烯单光子吸收系数为常数，约为6．8X107m-1，即单层石墨烯对入射光的吸收率约为213％；双层石墨烯的单光子吸收比单层石墨烯的单光子吸收强，且随入射光波长呈分段性变化．单层石墨烯的双光子吸收系数与波长r4成正比；双层石墨烯双光子吸收系数在红外波段（-3100nm处）有一个很强的共振吸收峰．研究结果可为石墨烯材料在光电子器件的研究和制作方面提供指导．

英文摘要：

We theoretically simulate one-photon and two-photon absorption spectra for monolayer and bilayer graphene employing the second-order perturbation theory of the electron-photon interaction. The tight-binding model is used to describe the band structure of graphene. The results show that one-photon absorption coefficient of monolayer graphene is a constant about 6.8 ~ 107 m-~, demon- strafing that the absorptivity of incident light in monolayer graphene approximates to 2.3%. The one-photon absorption coefficient of bilayer graphene changes sectionally with the wavelength and is greater than that of monolayer graphene. The two-photon absorption coefficient of monolayer graphene is proportional to ~4. The two-photon absorption coefficient of bilayer graphene exhibits a giant resonance absorption peak in the infrared （~3100 nm） region. Our results will provide theoretical guidance for the application of graphene in the research field of optoelectronic devices.