Wang Yalan, Li Xiang, Zhang Jin, Wo Jianghai
Opt Express. 2021 Mar 1;29(5):7535-7543. doi: 10.1364/OE.419334.
We propose and experimentally demonstrate a spurious level and phase noise improved Fourier domain mode-locked optoelectronic oscillator (FDML-OEO) based on a self-injection-locking (SIL) technique. The scheme applies a dual-loop FDML-OEO structure, in which a long optical fiber delay loop is used to injection-lock the OEO with a short oscillating optical fiber delay loop. SIL is achieved so long as the delay of the long loop is tuned at the integral multiple of the oscillation loop. The spur suppression ratio of the wideband linear frequency modulated (LFM) signal generated by the FDML-OEO can be improved by 14 dB under SIL. Furthermore, the modification of the spur suppression ratio depending on the injection power is also demonstrated. The phase noise of the proposed OEO is -127.5 dBc/Hz at 10 kHz offset, which is much improved comparing with a free-running OEO.
我们提出并通过实验证明了一种基于自注入锁定（SIL）技术的杂散电平与相位噪声得到改善的傅里叶域锁模光电振荡器（FDML-OEO）。该方案采用双环FDML-OEO结构，其中长光纤延迟环用于通过短振荡光纤延迟环对OEO进行注入锁定。只要长环的延迟调谐到振荡环的整数倍，就能实现自注入锁定。在自注入锁定条件下，FDML-OEO产生的宽带线性调频（LFM）信号的杂散抑制比可提高14 dB。此外，还展示了杂散抑制比随注入功率的变化情况。所提出的OEO在10 kHz频偏处的相位噪声为-127.5 dBc/Hz，与自由运行的OEO相比有了很大改善。
