基于狄拉克锥原理的1.3μm高速量子点光子晶体面发射激光器的研究

The surface-emitting lasers at 1.3μm is in great need for communication. However due to the drawback of the distributed Bragg reflectors (DBRs) and gain materials, such lasers do not have a good performance. In this project, we propose to use Dirac cone in photonic-crystal surface-emitting laser (PCSEL), combined with quantum dots (QDs) gain materials, to realize 1.3μm high-speed and low operating energy surface-emitting lasers. Such lasers can realize surface-emitting through Bragg diffraction without the need of thick DBR, resulting in lower loss and smaller series resistance. More importantly, by designing the radius of the air hole of photonic crystal, the Dirac cone can be realized, which in turn can enhance the spontaneous emission coupling efficiency, thus, the speed of PCSEL can be greatly increased. The concrete work involves the studying all-pathway QDs rate equations, the design and epitaxial growth of QDs, the design and the fabrication of air-hole photonic crystal and Dirac cone, and obtaining the technology of both epitaxial wafer and the device module of PCSEL. The signal modulation of the PCSEL is expected to be more than 50Gb/s and the operating energy of PCSEL is expected to be less than 100fJ/bit. Through this project, it is expected to meet the need of 1.3μm high-speed and low operating energy surface-emitting lasers in optical interconnects, which is considered to have both scientific value and economic benefits.

通讯领域对1.3μm面发射激光器有着强烈需求。然而由于分布式反馈反射镜（DBR）原因和增益介质因素，这种器件性能一直不佳。本项目提出基于狄拉克锥原理的光子晶体面发射激光器（PCSEL）结构，结合量子点增益介质，以期在1.3μm波段实现高速低功耗面发射激光输出。该器件通过布拉格衍射实现面发射，不需厚的DBR，具有低的吸收损耗和串联电阻。更关键的是，通过调控光子晶体空气孔半径实现狄拉克锥，可增强自发辐射耦合系数，有效提高PCSEL调制速率。本项目通过研究基于量子点全路径弛豫速率方程的器件性能模拟分析，优化量子点外延结构和生长条件，突破光子晶体狄拉克锥设计与制备工艺，获得高速PCSEL从外延到器件模块的整套技术，实现激光器调制速率>50Gb/s，传输功耗<100fJ/bit的研究目标。本项目的开展将有助于解决光互连领域缺少高速低功耗1.3μm面发射激光器的问题，具有重要的科学价值和经济效益。

光通讯领域对面发射激光器有着强烈需求。本项目主要开展面发射激光器的研究，包括：量子点全路径弛豫速率方程的器件性能模拟分析，优化量子点外延结构和生长条件，突破光子晶体设计与制备工艺，最终获得高速面发射激光器从外延到器件模块的整套技术。本项目实现量子点光子晶体面发射激光器13.3mW高功率输出，实现垂直腔面发射激光器50Gbit/s传输速率，100fJ/bit能耗的指标。本项目的研究成果为高速面发射激光器提供解决方案，具有重要的科学价值和经济效益。具体研究成果如下：.（1）通过光子晶体平坦带边模式和FP腔增强光场反馈，实现了量子点光子晶体面发射激光器创纪录的室温、连续条件下13.3mW功率输出。.（2）实现光子晶体面发射激光器脉冲条件下0.7°和1°超低发散角，获得激光器ns级脉冲条件下的响应特性。.（3）通过腔内光子寿命优化，实现高速垂直腔面发射激光器50Gbit/s传输速率和100fJ/bit的能耗。.（4）通过多孔径垂直腔面发射激光器设计，实现了单模、高功率、高速垂直腔面发射激光器。.在此项目支持下，共发表期刊和会议文章12篇，申请中国发明专利16项，授权中国发明专利13项，申请国际专利7项，授权国际发明专利3项，做国际会议邀请报告4人次，培养和硕士研究生11人。