Li He, Zhu Zihang, Gao Congrui, Wang Guodong, Zhou Tao, Li Xuan, Meng Qingqing, Zhou Yixiao, Zhao Shanghong
College of Information and Navigation, Air Force Engineering University, Xi'an 710077, China.
Key Laboratory of Electronic Information Control, Southwest China Research Institute of Electronic Equipment, Chengdu 610036, China.
Micromachines (Basel). 2023 Jan 28;14(2):339. doi: 10.3390/mi14020339.
A photonic approach to the cancellation of self-interference in the optical domain with fiber dispersion immunity and harmonic frequency down-conversion function is proposed based on an integrated, dual-parallel, dual-drive Mach-Zehnder modulator (DP-DMZM). A dual-drive Mach-Zehnder modulator (DMZM) is used as an optical interference canceller, which cancels the self-interference from the impaired signal before fiber transmission to avoid the effect of fiber transmission on the cancellation performance. Another DMZM is used to provide carrier-suppressed, local-oscillation (LO)-modulated, high-order double optical sidebands for harmonic frequency down-conversion to release the strict demand for high-frequency LO sources. By regulating the DC bias of the main modulator, the signal of interest (SOI) can be down-converted to the intermediated frequency (IF) band after photoelectric conversion with improved frequency-conversion efficiency, immunity to the fiber-dispersion-induced power-fading (DIPF) effect, and effective signal recovery. Theoretical analyses and simulation results show that the desired SOI in the X and K bands with a bandwidth of 500 MHz and different modulation formats can be down-converted to the IF frequency. The self-interference noise with the 2 GHz bandwidth is canceled, and successful signal recovery is achieved after a 10 km fiber transmission. The recovery performance of down-converted signals and the self-interference cancellation depth under different interference-to-signal ratios (ISRs) is also investigated. In addition, the compensation performance of DIPF is verified, and a 6 dB improvement in frequency conversion gain is obtained compared with previous work. The proposed scheme is compact, cost-effective, and thus superior in wideband self-interference cancellation, long-range signal transmission, and effective recovery of weak desired signals.
基于集成的双并行双驱动马赫-曾德尔调制器（DP-DMZM），提出了一种在光域中消除自干扰的光子学方法，该方法具有光纤色散免疫和谐波频率下变频功能。双驱动马赫-曾德尔调制器（DMZM）用作光干扰消除器，在光纤传输之前消除受损信号的自干扰，以避免光纤传输对消除性能的影响。另一个DMZM用于提供载波抑制、本地振荡（LO）调制的高阶双光边带，用于谐波频率下变频，以放宽对高频LO源的严格要求。通过调节主调制器的直流偏置，感兴趣信号（SOI）在光电转换后可以下变频到中频（IF）频段，具有提高的频率转换效率、对光纤色散引起的功率衰落（DIPF）效应的免疫能力以及有效的信号恢复。理论分析和仿真结果表明，X和K频段中带宽为500 MHz且具有不同调制格式的所需SOI可以下变频到IF频率。消除了带宽为2 GHz的自干扰噪声，在10 km光纤传输后实现了成功的信号恢复。还研究了不同干扰信号比（ISR）下下变频信号的恢复性能和自干扰消除深度。此外，验证了DIPF的补偿性能，与先前的工作相比，频率转换增益提高了6 dB。所提出的方案紧凑、经济高效，因此在宽带自干扰消除、远程信号传输和弱期望信号的有效恢复方面具有优势。
