基于SOI折叠外腔的增益耦合DFB窄线宽半导体激光器研究

Space laser communication, deep space exploration and earth-space integrated net work of measurement & control, requires increasing demands on data transmission speed & distance. It becomes key issue to obtain kHz-level narrow linewidth lasers with compact structure, low cost, low energy consumption and high stability. External cavity feedback semiconductor laser is regarded as the most promising solution to achieve ultra-narrow linewidth. Exiting studies mainly focus on the feedback by waveguide gratings, micro-disk resonators and fiber Bragg gratings, which all have the drawbacks of low efficiency, complex processing and poor stability. In order to solve these problems, we propose a novel narrow linewidth semiconductor laser based on SOI folded external cavity. Micro meter scale periodic electrode will induce gain coupled DFB laser chip. Folded external cavity on SOI helps to compress the chip’s linewidth. Studies will be carried out on the mechanism of narrow linewidth, single mode transmission, frequency noise reduction and electric properties of gain coupled DFB chips. This novel device is expected to implement 1550nm laser output with linewidth≤3kHz, side mode suppression ratio ≥40dB, relative intensity noise ≤-150dB/Hz. This project will provide a competitive laser source for space laser communication.

针对空间光通信、深空探测、天地空一体化测控网络等对数据传输速率和传输距离不断增加的需求，紧凑、低成本、低能耗和高稳定性的kHz量级窄线宽激光器的研究成为关键。外腔反馈半导体激光器成为获取窄线宽激光最有前景的方案。现有研究集中在波导光栅、微盘腔、光纤光栅反馈提供光注入，这些激光器存在效率低、稳定性差和制备工艺难度高的弊端。为此，本项目创新性提出构建基于SOI折叠外腔的增益耦合DFB窄线宽激光器。设计周期性微米级的电极结构，实现增益耦合机制的DFB芯片；在SOI上制备折叠外腔结构，压缩DFB芯片的线宽。该工作将在SOI折叠外腔压窄线宽、单模传输和降低频率噪声机理以及周期性电极条的增益耦合DFB激光器的电学特性机理的研究基础上开展；预计该新型器件可实现线宽≤3 kHz、边模抑制比≥40 dB、相对强度噪声≤-150 dB/Hz的1550nm波段激光。此研究将为空间光通信提供有竞争力的激光光源。

针对空间光通信、深空探测、天地空一体化测控网络等对数据传输速率和传输距离不断增加的需求，紧凑、低成本、低能耗和高稳定性的kHz量级窄线宽激光器的研究成为关键。外腔反馈半导体激光器成为获取窄线宽激光最有前景的方案。现有研究集中在波导光栅、微盘腔、光纤光栅反馈提供光注入，这些激光器存在效率低、稳定性差和制备工艺难度高的弊端。为此，本项目创新性提出构建基于SOI折叠外腔的增益耦合DFB窄线宽激光器。设计周期性微米级的电极结构，实现增益耦合机制的DFB芯片；在SOI上制备折叠外腔结构，压缩DFB芯片的线宽。该工作将在SOI折叠外腔压窄线宽、单模传输和降低频率噪声机理以及周期性电极条的增益耦合DFB激光器的电学特性机理的研究基础上开展；项目研制出1550 nm波段、线宽kHz量级的Bragg光栅外部光反馈注入锁定窄线宽半导体激光器。激光波长1550±1 nm，最高输出功率达11.71 mW@100 mA，边模抑制比（SMSR）为51.0 dB；积分线宽小于10 kHz@1 ms，最小洛伦兹线宽小于1 kHz，最小相对强度噪声（RIN）达-150 dBc/Hz。此研究将为空间光通信提供有竞争力的激光光源。