A flexibly frequency switchable active mode-locking optoelectronic oscillator with supermode noise suppression

• Published in: Optics and laser technology 2023-08, Vol.163, p.109354, Article 109354
• Main Authors: Xie, Tongtong, Dai, Weiyu, Zheng, Shichen, Wang, Haoran, Wu, Mengyuan, Huang, Chaohong, Fu, Hongyan
• Format: Article
• Language: English
• Subjects: Active mode-locking optoelectronic oscillator; Microwave photonics; Optoelectronic oscillator; Supermode noise suppression
• ISSN: 0030-3992; 1879-2545
• DOI: 10.1016/j.optlastec.2023.109354

•MFC signals with four switchable frequencies have been generated, which can be switched by simply rotating the PC.•By cascading a dual-loop structure, MFC signals with supermode noise suppression can be obtained.•By applying the longer length of the PMFs, the higher switchable central frequency of the MFC can be achieved. In this paper, we propose and experimentally demonstrate a flexibly frequency switchable active mode-locking optoelectronic oscillator (FSAML-OEO) in which a multi-passband microwave photonic filter (MPF) with two polarization-maintaining fibers (PMF) based Solc-Sagnac interferometer is used. Microwave frequency combs (MFCs) signals with four switchable central frequencies of 217 MHz, 453 MHz, 662 MHz and 1101 MHz are generated by controlling the polarization state of the Sagnac interferometer via rotating the polarization controller (PC). By cascading a dual-loop structure, MFCs signals with adjustable comb spacing of 1 MHz, 3 MHz, and 5 MHz are obtained with fundamental and harmonic FSAML-OEO, in which the supermode noise suppression ratios of the dominate modes and the super-modes are measured to be about 30 dB.