Opt Lett. 2018 May 15;43(10):2328-2331. doi: 10.1364/OL.43.002328.
A novel wideband tunable optoelectronic oscillator based on a microwave photonic filter (MPF) with an ultra-narrow passband is proposed and experimentally demonstrated. The single-passband MPF is realized by cascading an MPF based on stimulated Brillouin scattering and an infinite impulse response (IIR) MPF based on an active fiber recirculating delay loop. The measured full width at half-maximum bandwidth of the cascaded MPFs is 150 kHz. To the best of my knowledge, this is the first time realizing such a narrow passband in single-passband MPF. The oscillation frequency of the OEO can be tuned from 0 to 40 GHz owing to the wideband tunability of the MPF. Thanks to the ultrahigh mode selectivity of the IIR filter, the mode hopping is successfully suppressed. A stable microwave signal at 8.18 GHz is obtained with a phase noise of -113 dBc/Hz at 10 kHz, and the side mode noise is below -95 dBc/Hz. The signal-to-noise ratio exceeds 50 dB during the tuning process.
提出并实验演示了一种基于具有超窄通带的微波光子滤波器（MPF）的新型宽带可调谐光电振荡器。单通带 MPF 通过级联基于受激布里渊散射的 MPF 和基于有源光纤循环延迟环的无限脉冲响应（IIR）MPF 来实现。级联 MPF 的测量半最大值全带宽为 150 kHz。据我所知，这是首次在单通带 MPF 中实现如此窄的通带。由于 MPF 的宽带可调谐性，OEO 的振荡频率可以从 0 调谐到 40 GHz。由于 IIR 滤波器的超高模式选择性，成功抑制了模式跳变。在调谐过程中，信噪比超过 50 dB，获得了中心频率为 8.18 GHz、相位噪声为-113 dBc/Hz@10 kHz 的稳定微波信号，且边模噪声低于-95 dBc/Hz。
