Yin Feifei, Tu Dan, Liang Xiaodong, Dai Yitang, Zhang Junyi, Li Jianqiang, Xu Kun
Opt Express. 2015 May 4;23(9):11242-9. doi: 10.1364/OE.23.011242.
In this paper, a novel intermodulation-compensation optical receiver based on the bias-modulated photo detector (PD) is proposed and demonstrated to eliminate the third-order intermodulation (IMD3) for the intensity-modulation direct-detection (IMDD) analog photonic link. We directly extract the key nonlinear distortion from the distorted optical intensity by a low-pass optical receiver, which is used to modulate the home-made, high-speed PD with bias modulation. Inside the high speed PD, the distorted radio frequency (RF) band is mixed with the above extracted baseband signal, and the IMD3 elimination can be achieved. Our proposal is theoretically analyzed, and the performance of the bias-modulated PD is experimentally demonstrated. Spurious-free dynamic range (SFDR) of 123.4 dB within 1-Hz bandwidth is obtained with 18.1 dB improvement. A low-biased Mach-Zehnder modulator (MZM) is used, keeping a simple transmitter with an improved link gain. The proposed post linearization requires no digital processing, avoiding the high quantization noise.
本文提出并演示了一种基于偏置调制光电探测器（PD）的新型互调补偿光接收机，用于消除强度调制直接检测（IMDD）模拟光子链路中的三阶互调（IMD3）。我们通过一个低通光接收机直接从失真的光强中提取关键非线性失真，该接收机用于通过偏置调制来调制自制的高速PD。在高速PD内部，失真的射频（RF）频段与上述提取的基带信号混合，从而实现IMD3消除。我们的方案进行了理论分析，并通过实验演示了偏置调制PD的性能。在1 Hz带宽内获得了123.4 dB的无杂散动态范围（SFDR），提高了18.1 dB。使用了低偏置马赫-曾德尔调制器（MZM），保持了简单的发射机并提高了链路增益。所提出的后线性化不需要数字处理，避免了高量化噪声。
