双凹型谐振腔结构的金属半导体纳米激光器的数值仿真  

Numerical study of metallic semiconductor nanolasers with double-concave cavity structures

作　　者：张柏富 朱康 武恒 胡海峰 沈哲 许吉[2] Zhang Bai-Fu;Zhu Kang;Wu Heng;Hu Hai-Feng;Shen Zhe;Xu Ji(School of Electronic and Optical Engineering,Nanjing University of Science and Technology,Nanjing 210094,China;College of Electronic and Optical Engineering&College of Microelectronics,Nanjing University of Posts and Telecommunications,Nanjing 210023,China)

机构地区：[1]南京理工大学,电子工程与光电技术学院,南京210094 [2]南京邮电大学,电子与光学工程学院,微电子学院,南京210023

出　　处：《物理学报》2019年第22期286-293,共8页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:61604073,61805119,11404170);江苏省自然科学基金(批准号:BK20160839,BK20180469)资助的课题~~

摘　　要：近年来,金属半导体纳米激光器作为超小尺寸的光源被广泛地研究,其在光子集成回路、片上光互连、光通信等领域具有潜在的应用价值.随着谐振腔体积的减小,激光器损耗也迅速增加,这阻碍了激光器进一步的小型化.本文提出一种基于双凹型谐振腔的金属半导体纳米激光器结构.该结构具有圆柱形的反射端面和内凹的弯曲侧壁,能够使谐振模式集中于腔中心并减小辐射损耗,从而提升品质因子和降低激光器阈值.本文利用时域有限差分方法数值计算了三种不同曲线侧壁的双凹腔性能.数值仿真结果表明,相比于传统胶囊型腔结构,本文提出的双凹腔结构的品质因子提高24.8%,激光器阈值电流降低67.5%,能够有效提升激光器性能.该结构在超小型金属半导体纳米激光器领域具有重要应用价值.Metallic semiconductor nanolaser,as an ultra-small light source,has been increasingly attractive to researchers in last decade.It can have wide potential applications such as in photonic integrated circuits,onchip interconnect,optical communications,etc.One obstacle to miniaturization of the laser size is that the loss increases rapidly with the cavity volume decreasing.In previous studies,a type of Fabry-Perot cavity with capsule-shaped structure was investigated and demonstrated both numerically and experimentally,showing that its cavity loss is reduced dramatically in contrast to the scenario of conventional rectangular cavities.However,when the cavity size is reduced down to nanoscale,capsule-shaped structure surfers high loss.To overcome this difficulty,in this paper,a novel type of double-concave cavity structure for metallic semiconductor nanolaser in a 1.55μm wavelength range is proposed and numerically studied.The proposed structure consists of InGaAs/InP waveguide structure encapsulated by metallic clad,and has a cylindrical reflection end face and concave curved sidewalls.The cylindrical reflection end face can push the resonant mode into the cavity center and reduce the optical field overlap with metallic sidewalls,which can reduce the metallic loss.The curved-sidewalls topologically reduce the electric field component perpendicular to the sidewalls,and thus reducing the plasmonic loss.By optimizing the waist width of the double-concave cavity structure,the radiation loss can be effectively reduced,resulting in the improvement of cavity quality factor and the decrease of threshold current.Finite-difference time-domain simulations are conducted to investigate the properties of the proposed cavity structures such as resonant mode distribution,cavity quality factor,confinement factor,threshold gain and threshold current in this paper.The numerical results show that the double-concave cavity laser with cavity volume as small as 0.258 l3 increases 24.8%of cavity quality factor and reduces 67.5%of threshol

关 键 词：半导体激光器 微腔 表面等离激元 

分 类 号：TN2[电子电信—物理电子学]