新型半导体激光器及多功能光子集成基础研究

Whispering-gallery mode (WGM) microlasers have attracted a great attention for application as light sources in photonic integrated circuits and optical interconnects. However, directly modulated bandwidths are very low for WGM microlasers lasers in the present. Based on the investigation of directional emission microlasers and multiple-port microlasers, we will study multiple-function integration of the microlasers with the aim at realizing high speed modulation. We will investigate the control of directional emission efficiency and radiation loss for 3D microcavity structures, especially investigate the microcavity and coupled microcavities for enhancing the output coupling efficiency and the modulation bandwidth, and investigate the novel microcavity lasers integrated with light modulators. Semiconductor microlasers with the threshold current less than 1 mA at room temperature and that with the output power larger than 1 mW will be fabricated based on the optimization research of microcavity lasers; coupled-cavity microlasers will be studied based on the multiple-port microlasers, and the optical injection locking between two cavities in the coupled-cavity microlasers will be investigated for enhancing the 3dB bandwidth of direct modulation; the influence of the mode Q factor, loss, and the enhancement of spontaneous emission on the 3dB bandwidth will be studie with the aim of realizing 10Gb/s high speed modulation microlasers; semicondcutor microlasers integrated with absorption light modulators or Mach-Zehnder modulators will be studied and fabricated based on multiple-port microlasers; microlasers coupled to silicon optical waveguides will be studied based on wafer bonding technique and maskless laser process; furthermore, optical signal processing based on multiple-port microlasers will be studied, especially for optical wavelength transformation and optical bistability in integrated semiconductor microclasers.

回音壁微腔激光器作为光子集成及光互连的光源引起人们极大重视，但其高速直调速度一直较低。本项目将在定向及多端输出微腔激光器的研究基础上，开展微腔激光器的功能集成研究，目标是实现高速调制微腔激光器。我们将研究三维微腔耦合输出和辐射损耗控制，研究提高微腔及耦合微腔激光器的输出效率和调制带宽，并研究新型微腔激光器与光调制器的功能集成。要研制出阈值电流低于1mA的半导体微腔激光器和输出功率1mW以上的高效半导体微腔激光器；要研究利用多端口的微腔结构实现耦合微腔激光器,研究耦合微腔的注入锁定现象及注入锁定对激光器直接调制带宽的增强作用,实现10Gb/s的高速直调微腔激光器；要研究利用微腔激光器的输出波导制作电吸收或MZ型光调制器，实现微腔激光器与光调制器的功能集成；要研究利用键合技术和无掩模激光工艺技术实现微腔激光器与Si光波导的混合集成；研究多端口微腔激光器的光信息处理应用,特别是波长变换及光双稳。

本项目针对现代信息技术中光互连的发展对高带宽低能耗小集成光源的需求，利用回音壁模式的光学微腔小体积、高品因子和适合平面集成等优点，研究基于光学微腔的新型半导体激光器及其集成技术。主要研究光学微腔的模式光场分布及输出特性，设计激光器谐振腔和耦合波导结构，研究半导体激光器的微纳加工技术，实现激光器的激射光谱控制，研制新型半导体激光器并研究其在光电子集成中的应用。主要取得的成果包括：研制出调制带宽超过20GHz，调制速率30Gb/s的高速直调微腔激光器；研制出阈值电流小于1mA，边模抑制比大于30dB的圆柱形微腔激光器；研制出输出功率达8mW的耦合微腔激光器，并实现波长的10nm范围连续可调；研制出集成互注入耦合微盘激光器，研究了其在不同波长失谐下的非线性过程。研究成果为将新型半导体激光器及其集成器件在高带宽低能耗的片上光互连奠定基础。本项目研究中共发表SCI检索论文49篇，培养博士研究生8名，其中3名获得中科院院长优秀奖，1名获得中科院优秀博士论文。