基于光注入半导体激光器产生窄线宽微波信号

发布时间：2018-05-20 06:59

本文选题：光注入半导体激光器 + 单周期(P1)振荡　；参考：《西南大学》2015年硕士论文

【摘要】：近年来,一种新兴的光载无线(Radio-over-Fiber, RoF)技术逐渐受到人们的广泛关注,其采用光纤链路传输无线电信号,能够将光纤通信和微波通信良好结合起来。由于RoF具有抗干扰性强、保密性强、覆盖面积广、低成本易安装等优点,因此逐渐成为通信技术的研究热点。RoF技术中的关键一项便是光微波的获取,最近,一种基于光注入半导体激光器所表现的单周期(P1)振荡非线性动力学状态获取微波信号的方法受到相关领域学者的广泛关注。利用该方法不仅可以直接产生具有单边带(SSB)光谱结构的微波信号而且其频率高、连续可调,然而这种方法产生的微波信号频率不够稳定、需要引入额外的频率锁定技术。本文首先基于L-K模型,理论研究了利用光纤布拉格光栅(FBG)反馈对外光注入半导体激光器产生的微波信号进行频率锁定的技术。结果表明,通过调节注入强度,光注入半导体激光器能够产生连续可调的微波信号；通过引入微弱的FBG反馈且精细调节反馈强度,微波线宽将从MHz量级被压缩到几十kHz。进一步的,我们分析了反馈强度及反馈时间对微波线宽的影响。此外,本文还提出了一种1/2次谐波锁定技术,即采用一个频率是光注入半导体激光器单周期振荡频率1/2的次谐波信号对所得到的微波信号进行频率锁定。实验结果显示：在合适的注入条件,处于单周期振荡的光注入半导体激光器可输出光谱具有单边带(SSB)结构的光生微波信号,但微波信号的线宽比较宽(MHz量级)；通过采用频率为单周期振荡频率一半的次谐波信号调制光注入半导体激光器,可将微波线宽从十几MHz压缩到几十kHz.进一步地,我们分析了次谐波调制信号的功率以及频率对微波信号的相位噪声的影响,并在由次谐波调制信号的功率和频率构成的参数空间绘制出了能实现次谐波频率锁定的分布区域。
[Abstract]:In recent years, a new technology of radio-over-Fiber (RoFF) has been paid more and more attention. It uses optical fiber link to transmit radio signal, which can combine optical fiber communication with microwave communication. Because RoF has the advantages of strong anti-interference, strong confidentiality, wide coverage, low cost and easy installation, it has gradually become the research hotspot of communication technology .ROF technology is the acquisition of optical microwave. A method for obtaining microwave signals based on the nonlinear dynamic state of single period P1 oscillation of optical injection semiconductor lasers has been paid much attention by researchers in related fields. Not only can the microwave signal with single sideband SSBs spectral structure be directly generated by this method, but its frequency is high and continuously adjustable. However, the frequency of the microwave signal generated by this method is not stable enough, so it is necessary to introduce additional frequency locking technique. Firstly, based on the L-K model, the frequency locking technique of the microwave signal generated by external optical injection semiconductor laser using fiber Bragg grating (FBG) feedback is studied in this paper. The results show that the optical injection semiconductor laser can produce continuously adjustable microwave signal by adjusting the injection intensity, and by introducing weak FBG feedback and fine adjusting the feedback intensity, the microwave linewidth will be compressed from the order of MHz to tens of kHz. Furthermore, we analyze the effect of feedback intensity and feedback time on microwave linewidth. In addition, a 1 / 2 harmonic locking technique is proposed, in which the frequency of the microwave signal is locked by a subharmonic signal with a frequency of 1 / 2 of the single-period oscillation frequency of an optical injection semiconductor laser. The experimental results show that the optical injection semiconductor laser with single cycle oscillation can output the photogenerated microwave signal with single sideband SSBs structure under suitable injection conditions. However, the line width of microwave signal is wider than that of MHz, and the microwave linewidth can be compressed from more than ten MHz to tens of kHz by injecting subharmonic signal modulated light into semiconductor laser with frequency half of the frequency of single-period oscillation frequency. Furthermore, we analyze the influence of the power and frequency of the subharmonic modulation signal on the phase noise of the microwave signal. In the parameter space which is composed of the power and frequency of the subharmonic modulation signal, the distribution region which can realize the frequency locking of the subharmonic is plotted.
【学位授予单位】：西南大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN248.4

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