Kwon Oh Kee, Lee Chul Wook, Oh Su Hwan, Kim Ki Soo
Opt Express. 2021 Jan 18;29(2):1805-1812. doi: 10.1364/OE.414989.
We report a tunable distributed Bragg reflector-laser diode (DBR-LD) integrated with an electro-absorption-modulator (EAM) at an operating wavelength of 1.3 µm. This LD consists of gain, phase control (PC), DBR, and EAM sections, realized by using a butt-coupling technique in monolithically integrating the multiple quantum wells (MQWs) with the passive core and by applying an etched-mesa buried hetero-structure (EMBH) to the resonance cavity (i.e., gain to DBR section) and a deep-ridge type to the EAM section in fabricating the waveguide structure. Wavelength tuning of the LD is achieved by both applying a voltage to the heater metal of DBR section (coarse tuning) and injecting a current to the ohmic metal of PC section (fine tuning). From the work, the fabricated chips show a threshold current of about 13 mA, a side mode suppression ratio (SMSR) of more than 35 dB, and a tuning range of 15 nm within a heater voltage of 2 V. Dynamic tests for the EAM-integrated LD show the 3 dB bandwidth of more than 20 GHz and clear 25 Gb/s eye openings with a dynamic extinction ratio (DER) of over 7 dB for 16 channels spaced at the wavelength interval of 0.55 nm. Based on these results, we conclude that the EAM-integrated DBR-LD is capable of providing 16 channel operation at a data rate of 25 Gb/s and can be used as an effective light source for WDM-based mobile front-haul networks.
我们报道了一种工作波长为1.3 µm的、集成了电吸收调制器（EAM）的可调谐分布布拉格反射器激光二极管（DBR-LD）。该激光二极管由增益、相位控制（PC）、DBR和EAM部分组成，通过采用对接耦合技术将多量子阱（MQW）与无源纤芯进行单片集成，并在制造波导结构时将刻蚀台面掩埋异质结构（EMBH）应用于谐振腔（即增益到DBR部分），将深脊型结构应用于EAM部分来实现。通过向DBR部分的加热金属施加电压（粗调）和向PC部分的欧姆金属注入电流（微调）来实现激光二极管的波长调谐。从这项工作来看，所制造的芯片显示出阈值电流约为13 mA，边模抑制比（SMSR）超过35 dB，在2 V的加热电压下调谐范围为15 nm。对集成EAM的激光二极管进行的动态测试表明，其3 dB带宽超过20 GHz，对于波长间隔为0.55 nm的16个通道，在动态消光比（DER）超过7 dB时能清晰地实现25 Gb/s的眼图张开。基于这些结果，我们得出结论，集成EAM的DBR-LD能够以25 Gb/s的数据速率提供16通道运行，并且可以用作基于波分复用（WDM）的移动前传网络的有效光源。
