基于光学谐振腔的光电振荡器研究

发布时间：2018-08-14 15:41

【摘要】：光电振荡器(Optoelectronics Oscillator,OEO)作为一种新型的微波信号源,可以产生频率高达几百GHz、超高频谱纯度的射频信号和微波光子信号。而低相位噪声、高频谱纯度、高品质因数的微波信号又被广泛的应用于宇宙探测、军事雷达、航空航天、通讯系统和电子对抗等领域。随着射频通信的快速发展,近年来对于OEO的研究从降低相位噪声转移到实现可调谐输出以及小型化和实用化过程中。论文首先介绍了光电振荡器的基本概念,探讨了OEO的基本工作原理和应用领域。之后针对OEO系统中长光纤存在占用系统体积过大,容易受外界环境温度和应力影响等问题,结合光学谐振腔的光学性质,提出了利用光学谐振腔替换长光纤作为OEO系统延时器件的方案。论文重点开展了不同长度光纤在OEO系统延时效应的研究,用实验数据分析了不同延时效应对微波信号指标的影响。为了提高光子在光学谐振腔中的延时效果,实验中设计了锁频调制系统,使光子始终处于光学谐振腔的谐振点上。实验测试结果表明:使用品质因数(Q值)为107光学谐振腔最多可以替换388米的长光纤。对于未来光电振荡器体积的小型化具有潜在的意义。在此基础上,论文结合透射式光学谐振腔的光学特性,进一步研究了基于光学谐振腔的可调谐光电振荡器实验方案。提出了利用相位调制器串联透射式光学谐振腔的方案,利用光子滤波替换电滤波,以取代传统系统中的强度调制器和滤波器,实现了系统结构的优化。测试结果表明:优化后的系统可以输出10GHz单模式微波信号,还可以实现步长为23MHz的可调谐,实验结果验证了所提方案的正确性。论文最后分析了光电振荡器的系统噪声,并针对本文所提的基于光学谐振腔的光电振荡器系统,设计了温控和锁频两种优化系统相位噪声的方案。对比了两种优化方案的去相位噪声效果,实验结果显示:加入锁频系统后的OEO,在中心频率10GHz附近微波信号的相位噪声为-109.26dBc/Hz@10kHz。通过在OEO系统中引入光波导谐振腔,可以使整个OEO系统尺寸缩小到:21×9.5×7 cm3,为光电振荡器的小型化和实用化发展提供了一种新的思路。
[Abstract]:As a new type of microwave signal source, Optoelectronics oscillator can produce RF signal and microwave photon signal with frequency up to several hundred GHz and ultra-high spectral purity. However, microwave signals with low phase noise, high spectral purity and high quality factor are widely used in space exploration, military radar, aerospace, communication systems and electronic countermeasures. With the rapid development of RF communication, the research on OEO has shifted from phase noise reduction to tunable output, miniaturization and practicality in recent years. In this paper, the basic concept of optoelectronic oscillator is introduced, and the basic working principle and application field of OEO are discussed. In view of the problem that the long optical fiber in OEO system occupies too much volume and is easily affected by the external environment temperature and stress, the optical properties of the optical resonator are combined. A scheme of replacing long fiber optic fiber with optical resonator as delay device in OEO system is proposed. In this paper, the delay effect of fiber with different lengths in OEO system is studied, and the influence of different delay effect on microwave signal index is analyzed with experimental data. In order to improve the delay effect of photons in the optical resonator, a frequency locking modulation system is designed in the experiment, which makes the photon always at the resonance point of the optical resonator. The experimental results show that the use of a quality factor (Q) of 107 optical resonators can replace up to 388 meters of long optical fiber. It has potential significance for the miniaturization of optoelectronic oscillator volume in the future. On this basis, combining the optical characteristics of the transmission optical resonator, the experimental scheme of the tunable optoelectronic oscillator based on the optical resonator is further studied. A series transmission optical resonator with phase modulator is proposed. The photon filter is used to replace the electric filter to replace the intensity modulator and filter in the traditional system. The structure of the system is optimized. The test results show that the optimized system can output 10GHz single-mode microwave signal and realize the tunable step size of 23MHz. The experimental results verify the correctness of the proposed scheme. Finally, the system noise of the optoelectronic oscillator is analyzed, and two schemes of temperature control and frequency locking are designed for the optoelectronic oscillator system based on the optical resonator proposed in this paper. The experimental results show that the phase noise of microwave signal near the center frequency 10GHz is -109.26 dBcr / Hz @ 10kHz. By introducing the optical waveguide resonator into the OEO system, the size of the whole OEO system can be reduced to 21 脳 9.5 脳 7 cm ~ 3, which provides a new way of thinking for the miniaturization and practical development of the optoelectronic oscillator.
【学位授予单位】：中北大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN752

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