Chen Guanyu, Yu Yu, Zhang Xinliang
Wuhan National Laboratory for Optoelectronics &School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan 430074, China.
Sci Rep. 2016 May 20;6:26469. doi: 10.1038/srep26469.
We propose and fabricate a silicon based dual-detector optical receiver, which consists of a two dimensional (2D) grating coupler (GC) and two separate germanium photodetectors (Ge PDs). The 2D GC performs polarization diversity, and thus demultiplexing and detection for polarization division multiplexed (PDM) signals can be achieved. Through a specific design with double-sides illumination, the space charge density can be reduced and the responsivity and saturation power can be improved significantly. The measured dark current, responsivity and bandwidth are 0.86 μA, 1.06 A/W and 36 GHz under 3 V reverse biased voltage, respectively. Both DC currents and eye diagrams are measured for the proposed device and the results validate its performance successfully. The power penalty between the single and dual polarized signals is about 1.9 dB under 10 and 20 Gb/s cases for both the two Ge PDs. The proposed direct detection (DD) for PDM signals with high speed, high responsivity and large saturation power is cost-effective and promising for short reach optical communication.
我们提出并制造了一种基于硅的双探测器光接收器，它由一个二维（2D）光栅耦合器（GC）和两个独立的锗光电探测器（Ge PDs）组成。二维光栅耦合器实现偏振分集，因此可以实现偏振复用（PDM）信号的解复用和检测。通过双面照明的特定设计，可以降低空间电荷密度，并显著提高响应度和饱和功率。在3V反向偏置电压下，测得的暗电流、响应度和带宽分别为0.86μA、1.06A/W和36GHz。对所提出的器件测量了直流电流和眼图，结果成功验证了其性能。对于两个锗光电探测器，在10Gb/s和20Gb/s情况下，单偏振信号和双偏振信号之间的功率代价约为1.9dB。所提出的用于PDM信号的直接检测（DD）具有高速、高响应度和大饱和功率，对于短距离光通信具有成本效益且前景广阔。
