Li Qi-Zhu, Huang Yuan-Qing, Ning Ji-Qiang, Jiang Cheng, Wang Xu, Chen Hong-Mei, Li Xiao, Zhang Rui-Ying, Zhang Kai, Min Jia-Hua, Peng Yong, Zhang Zi-Yang
Key Laboratory of Nanodevices and Applications, Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences, Suzhou, 215123, People's Republic of China.
School of Materials Science and Engineering, Shanghai University, 200444, Shanghai, People's Republic of China.
Nanoscale Res Lett. 2018 Sep 4;13(1):267. doi: 10.1186/s11671-018-2674-3.
In this paper, a laterally coupled distributed feedback (LC-DFB) laser based on modulation p-doped multiple InAs/GaAs quantum dot (QD) structures has been fabricated. The device exhibits a high side-mode suppression ratio (SMSR) of > 47 dB and a high thermal stability of dλ/dT = 0.092 nm/K under continuous-wave (CW) operation, which is mainly attributed to the high material gain prepared by modulation p-doping and rapid thermal annealing (RTA) process, and the significantly reduced waveguide losses by shallow-etched gratings and its close proximity to the laser ridge feature in the LC-DFB laser. With this superior performance of the DFB laser, the wide tunable dual-wavelength lasing operation has been obtained by delicately defining different periods for the grating structures on the two sides of the laser ridge or combining the reduced laser cavity length. The wavelength spacing between the two lasing modes can be flexibly tuned in a very wide range from 0.5 to 73.4 nm, corresponding to the frequency difference from 0.10 to 14 THz, which is the largest tuning range by the utilization of single device and hence providing a new opportunity towards the generation of CW THz radiation.
本文制备了一种基于调制p型掺杂多InAs/GaAs量子点（QD）结构的横向耦合分布反馈（LC-DFB）激光器。该器件在连续波（CW）工作下表现出大于47 dB的高边模抑制比（SMSR）和dλ/dT = 0.092 nm/K的高热稳定性，这主要归因于通过调制p型掺杂和快速热退火（RTA）工艺制备的高材料增益，以及浅蚀刻光栅显著降低的波导损耗及其与LC-DFB激光器中激光脊特征的紧密接近。凭借DFB激光器的这种优异性能，通过巧妙地定义激光脊两侧光栅结构的不同周期或结合缩短的激光腔长度，实现了宽可调谐双波长激光运转。两个激光模式之间的波长间距可以在0.5至73.4 nm的非常宽的范围内灵活调谐，对应于0.10至14 THz的频率差，这是利用单个器件实现的最大调谐范围，从而为连续波太赫兹辐射的产生提供了新的机会。
