光抽运多层石墨烯太赫兹表面等离子体增益特性的研究  

Study on the gain characteristics of terahertz surface plasma in optically pumped graphene multi-layer structures

作　　者：刘亚青[1,2] 张玉萍[2] 张会云[2] 吕欢欢[2] 李彤彤[2] 任广军[1] 

机构地区：[1]天津理工大学电子信息工程学院,天津300384 [2]山东科技大学电子通信与物理学院青岛市太赫兹技术重点实验室,青岛266510

出　　处：《物理学报》2014年第7期233-239,共7页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:61001018);山东省自然科学基金(批准号:ZR2011FM009,ZR2012FM011);山东科技大学杰出青年科学基金(批准号:2010KYJQ103);山东科技大学科研创新团队支持计划项目(批准号:2012KYTD103);山东省高等学校科技计划项目(批准号:J11LG20);青岛市科技计划项目(批准号:11-2-4-4-(8)-jch);青岛经济技术开发区重点科技计划项目(批准号:2013-1-64);山东科技大学基金(批准号:YCB120173)资助的课题~~

摘　　要：本文建立了光抽运多层石墨烯表面等离子体模型,计算了光抽运多层石墨烯等离子体传播系数的实部和吸收系数,讨论了动量弛豫时间、温度、层数、准费米能级对表面等离子体传播系数的实部和吸收系数的影响.研究结果表明,光抽运多层石墨烯使其动态电导率的实部在太赫兹频段内出现负值时,石墨烯表面等离子体实现增益.通过光抽运剥离层石墨烯和含有底层石墨烯结构表面等离子体传播系数和吸收系数比较,表明光抽运剥离层石墨烯能更有效地实现表面等离子体的增益.同时,在低温下,光抽运具有合适层数的石墨烯比光抽运单层石墨烯能获得更大的表面等离子体增益.Based on the developed optically pumped graphene multilayer terahertz surface plasma structures, this paper calculates the real part of propagation index and amplification coefficient in optically pumped graphene multilayer structures, discusses the influences of momentum relaxation time, temperature, numbers of grapheme layers, and the quasi-Fermi energy in the topmost grapheme layer on the real part of propagation index and amplification coefficient. It is shown that when the real part of dynamic conductivity becomes negative in the terahertz range of frequencies in the optically pumped graphene multilayer structures, the surface plasma of graphene layers can achieve gain, By comparing the peeling-graphene-structure with the graphene structure that has a high conducting bottom graphene layer in optically pumped scheme, it can be said that the surface plasma of the peeling-graphene-structure can get a high efficient amplification. Meanwhile, the structure having properly numbers of graphene layers can get a larger amplification than the single graphene structure in an optically pumped scheme at low temperatures.

关 键 词：太赫兹 多层石墨烯 表面等离子体 增益 

分 类 号：O53[理学—等离子体物理]