A novel photonics-assisted method for frequency up/down-conversion based on an integrated dual-polarization dual-parallel Mach–Zehnder modulator (DP-DPMZM) with tunable optoelectronic oscillator (OEO) and phase shift is presented. The local oscillator (LO) signal with high spectral purity and low phase noise is generated by an OEO loop in one of the sub-DPMZMs. The frequency can be adjusted by an electrical bandpass filter (EBPF). The radio frequency (RF) signal is injected into another sub-DPMZM. The carrier-suppressed single-sideband (CS-SSB) modulation of both the LO and RF signals is achieved. The phase of the converted signal can be tuned by an integrated dual-channel phase modulator (DPM). Frequency up/down-conversion can be switched by tuning a single bias voltage of the DP-DPMZM. Multiple functions, including tunable LO signal generation, up/down-conversion and phase shifting, can be realized. Moreover, dispersion-induced power fading is well compensated due to CS-SSB modulation. In the experiments, the tunable LO signal from 5 to 18 GHz, with a sidemode suppression ratio as high as 46.1 dB and a phase noise level of −104.5 dBc/Hz @ 10 kHz at 10 GHz, is generated successfully. The spur suppression ratios of the up/down-converted signals are 32.6 dB and 35.6 dB, respectively. The up/down conversion performance for RF carrying 16 quadrature amplitude modulation (16-QAM) signal is also investigated. The phase shifting of dual-channel converted signals can be varied continuously and independently in the range of 0–360°, and the phase deviation is ±1.8°. The proposed compact link is characterized by function multiplexing and inherent dispersion compensation.

中文翻译：

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具有可调 OEO 和相移的光子辅助上/下变频


提出了一种基于具有可调谐光电振荡器（OEO）和相移的集成双偏振双并行马赫-曾德调制器（DP-DPMZM）的新型光子辅助上/下变频方法。具有高频谱纯度和低相位噪声的本地振荡器 (LO) 信号由其中一个 sub-DPMZM 中的 OEO 环路生成。频率可以通过电子带通滤波器（EBPF）进行调整。射频 (RF) 信号被注入另一个子 DPMZM。实现了 LO 和 RF 信号的载波抑制单边带 (CS-SSB) 调制。转换信号的相位可以通过集成双通道相位调制器 (DPM) 进行调谐。通过调节 DP-DPMZM 的单个偏置电压可以切换上/下变频。可以实现多种功能，包括可调LO信号生成、上/下变频和相移。此外，由于 CS-SSB 调制，色散引起的功率衰落得到了很好的补偿。在实验中，成功生成了5至18 GHz的可调谐本振信号，其边模抑制比高达46.1 dB，相位噪声水平在10 kHz @ 10 GHz时为−104.5 dBc/Hz。上变频/下变频信号的杂散抑制比分别为32.6 dB和35.6 dB。还研究了携带 16 正交幅度调制 (16-QAM) 信号的 RF 的上/下变频性能。双通道转换信号的相移可在0~360°范围内连续独立变化，相位偏差为±1.8°。所提出的紧凑链路的特点是功能复用和固有的色散补偿。