飞秒激光泵浦剥离层石墨烯实现太赫兹波放大的研究  

Study of terahertz wave amplification realized by pumping peeling-graphene-layer structure with femto-second laser

作　　者：张玉萍[1] 刘陵玉[1] 张晓[1] 张洪艳[1] 张会云[1] 

机构地区：[1]山东科技大学理学院青岛市太赫兹技术重点实验室,山东青岛266510

出　　处：《光电子．激光》2012年第5期832-838,共7页Journal of Optoelectronics·Laser

基　　金：国家自然科学基金(61001018;60637010);国家"973"计划(2011CB933101);山东省自然科学基金(ZR2011FM009);山东科技大学杰出青年科学基金(2010KYJQ103);山东省高等学校科技计划(J11LG20);青岛市科技计划(11-2-4-4-(8)-jch;10-3-4-2-1-jch)资助项目

摘　　要：基于光激发石墨烯的瞬态电子-空穴的弛豫/复合过程中,在Dirac点附近形成粒子数反转并产生THz波段负动态电导率的机理,研究剥离层石墨烯在室温条件下实现THz波段电磁波的受激放大。理论推导了剥离层石墨烯动态电导率的表达式,并研究了动态电导率随信号波长、石墨烯层数和泵浦光强度的变化关系,对单层和多层石墨烯结构作了分析比较。分析了与动态电导率有关的增益并进行了数值计算与模拟。研究表明,在室温条件下,剥离层石墨烯可以实现THz波段电磁波的有效放大。Based on the mechanism of achieving population inversion near the Dirac point and producing negative dynamic conductivity within the terahertz（THz） range as a result of the transient relaxation/recombination of optically excited electrons and holes,we realize the electromagnetic wave amplification at the region of THz frequency at room temperature by pumping peeling-graphene-layer structure.The expression for the dynamic conductivity of peeling-graphene-layer structure is given and relations between the dynamic conductivity and wavelength,the number of graphene layers and the optical pumping intensity are considered.We make an analysis and comparison between monolayer and multilayer structures.The gain of the structure in connection with dynamic conductivity is calculated and simulated.Results indicate that the peeling-graphene-layer structure might be used to realize the terahertz wave amplification with a high efficiency at room temperature.

关 键 词：太赫兹(THz)波放大 受激放大 负动态电导率 石墨烯 

分 类 号：O432[机械工程—光学工程] TN24[理学—光学]