Ye Fan, Cheng Fengmin, Jia Zhiwei, Zhang Jinchuan, Zhuo Ning, Liu Fengqi, Zheng Youdou, Shi Yi
School of Electronic Science and Engineering Nanjing University, Nanjing, Jiangsu 210093, People's Republic of China.
Key Laboratory of Semiconductor Materials Science, Chinese Academy of Sciences, Institute of Semiconductors, Beijing 100083, People's Republic of China.
Nanophotonics. 2023 Mar 28;12(10):1903-1912. doi: 10.1515/nanoph-2023-0077. eCollection 2023 May.
We report on an index-coupled distributed feedback (DFB) quantum cascade lasers (QCLs) of high single-mode stability by using of a grating reflector (GR) to reflect effectively light of a specific wavelength. Fabrications of the QCLs were performed with ∕4 equivalent phase shift (EPS) or sampled Moiré grating (SMG) structure, which regulates the light intensity distribution in the cavity and coupling strength. Both EPS-GR and SMG-GR QCLs demonstrate a high emission wavelength precision and a side-mode-suppression-ratio (SMSR) of 24.5 dB at the injection current of 5 A and the pulse width of 5 μs, offering considerable output power even at the edge of the gain spectrum. Furthermore, we investigated the arrays of EPS-GR and SMG-GR QCLs with lower threshold current and higher output power by introducing semi-insulated InP (Fe) ranging from 8.25 to 8.67 μm and 8.16-8.63 μm, respectively. The present QCLs via a GR are prospective for applications requiring single-mode stability and wide tunability.
我们报道了一种通过使用光栅反射器（GR）有效反射特定波长光的指数耦合分布反馈（DFB）量子级联激光器（QCL），其具有高单模稳定性。QCL的制备采用了1/4等效相移（EPS）或采样莫尔光栅（SMG）结构，该结构可调节腔内光强分布和耦合强度。在5 A注入电流和5 μs脉冲宽度下，EPS-GR和SMG-GR QCL均表现出高发射波长精度和24.5 dB的边模抑制比（SMSR），即使在增益谱边缘也能提供可观的输出功率。此外，我们通过分别引入范围为8.25至8.67μm和8.16 - 8.63μm的半绝缘InP（Fe），研究了具有较低阈值电流和较高输出功率的EPS-GR和SMG-GR QCL阵列。通过GR的当前QCL对于需要单模稳定性和宽可调性的应用具有前景。
