【作者】 李晶；

【导师】 宁提纲；

【作者基本信息】 北京交通大学 ， 通信与信息系统， 2013， 博士

【摘要】 微波光子学将微波学和光子学融合在一起,成为一个全新的技术领域,为光子技术和微波、毫米波的集成在远程宽带通信、射电天文学、微波/毫米波成像和雷达系统等民用和军用领域的发展打开了一扇神奇的、充满希望的大门。作为一门新兴的学科,其研究范围包括微波光子发生器、微波/毫米波频段的光电子器件、光控微波器件、光载无线(RoF)通信系统等。本文结合所承担的国家自然科学基金重点项目和面上项目,针对微波光子发生器和可调光载波边带比(OCSR)光单边调制技术,开展了一系列深入的理论、仿真及实验研究,取得的主要创新成果如下：1、提出并研究了两种基于高斯电脉冲调制的脉冲无线电超宽带(IR-UWB)光子发生器结构,两种结构分别利用了调制器的线性调制区域和两类特殊调制区域,应用相位调制-强度调制映射关系及脉冲波形构造原理,获得了IR-UWB脉冲。各方案中,改变高斯电脉冲的相对时延都可实现IR-UWB脉冲的正负极性或波形之间的切换。2、提出并研究了两种基于连续光射频调制的周期性三角形光脉冲串光子发生器结构,两种结构分别利用了光纤色散所致的射频功率衰落效应和偏振复用及偏振调制的特性,实现了光强度表达式向三角形傅立叶级数的有效逼近,获得了重复频率二倍于射频调制频率的周期性三角形光脉冲串。3、提出并研究了两种具有非相干双光源结构的八倍频毫米波光子发生器结构,两种结构分别对现有的二次外差技术和前向调制技术进行了改进,利用各自在消除相位噪声方面的特性,抵消两个激光器各自的相位噪声,获得八倍于射频调制频率的毫米波信号,由于其频率与光源波长间隔无关,频率稳定性高。4、实验制作了一个具有倒三角形透射谱的啁啾光纤光栅,并将其应用于光单边带滤波以及OCSR调节中,该方案利用该光栅透射谱范围内大的负向斜边,在实现光单边带滤波的同时也降低了OCSR,可提高RoF模拟光链路的接收灵敏度。5、实验制作了一个保偏光纤光栅,并将其应用在可调OCSR的光单边带调制技术中,光栅首先将光单边带调制信号的光载波与调制光边带分离并置于两个正交的偏振态上,然后利用反射谱偏振相关特性对单边带调制信号OCSR进行大范围调谐,可提高RoF模拟光链路的接收灵敏度。此外,论文还对多个副载波复用的情况下的OCSR进行了分析和研究。6、实验研究了一种基于双平行马赫曾德尔调制器的可调OCSR光单边带调制方案,方案利用调制器内部的三个独立调制单元,分别实现光单边带调制、光载波移相和光信号干涉,改变其中一个调制单元的偏置点,可实现OCSR在-20.8～23.5dB范围内动态可调,提高光链路的接收灵敏度。更多还原

【Abstract】 Microwave Photonic is an inter-disciplinary field of study which combines microwave engineering and photonic technology together. It is considered as a prospective subject who can find many applications in both military and civilian areas, such as remote broadband communication, radio astronomy, micro/millimeter-wave imaging and radar system. As an interdisciplinary subject, its research effect covers microwave photonic generator, microwave optoelectronic devices, and radio over fiber system. Under the supports of the National Nature Science Foundation of China, this thesis is devoted to investigate new prototype of microwave photonic generator and optical single sideband modulation with tunable optical carrier-to-sideband ratio (OCSR), by theory, simulation and experiment. The main innovative research efforts are summarized as follows:1. Two novel structures of impulse-radio ultra-wideband (IR-UWB) photonic generator have been analyzed and verified. Both two structures utilize the transmission function of typical modulators but in different modulation areas. In both two proposals, IR-UWB pulses can be obtained by using PM-IM mapping or pulse shape construction. By tuning the relative time delay between two paths of the Gaussian driving pulses, the IR-UWB pulse’s polarity and waveform can be switched easily.2. Two novel structures of periodic triangular-shaped pulse sequence generator based on continuous-wave laser modulation have been analyzed and verified. In both two proposals, optical carrier-suppression (OCS) modulation and fiber characteristic are employed, making the expression of output optical intensity approximately equals to the Fourier expansion of idea triangular-shaped pulses. In our work, periodic triangular-shaped pulse sequence with repetition rate twice of driving frequency can be obtained.3. Two improved structures of millimeter-wave photonic generator with frequency8-tupling have been analyzed and verified. Both two proposals employ two phase-uncorrelated lasers as source, which is characterized as totally different phase noise. In our work, we make improvement on the original prototypes (two-step heterodyne and feed-forward modulation) and introduce the idea of eliminating phase noise in millimeter-wave generation with frequency8-tupling. Since the frequency is independent on the wavelength division of laser source. Frequency stability can be guaranteed.4. A chirped fiber grating with triangular-shaped spectrum has been fabricated and utilized in RoF analog photonic link. By using the negative slop in the spectrum, optical single sideband (OSSB) modulation and a reduced OCSR can be obtained simultaneously, which improve the link sensitivity consequently.5. A polarize-maintained fiber grating (PM-FBG) has been fabricated and utilized in RoF analog photonic link. The functionality of PM-FBG is to separate and allocate optical carrier and sideband with orthogonal polarization. By simply tuning the inject polarization of OSSB signal, the target OCSR can be continuously tuned, which improve receiver sensitivity a lot. Besides, we also discuss the issue of the optimized OCSR in RoF analog photonic link when multi-subcarrier modulation is applied.6. A novel prototype of optical single sideband modulation with tunable OCSR has been proposed and verified. The proposal requires only one dual-parallel Mach-Zehnder modulator (DP-MZM) as the key component. By employing the three separate modulation units in the DP-MZM, optical single sideband modulation, optical carrier phase shifting and lightwave interference can be achieved at the same time. The OCSR can be simply tuned by changing the bias voltages of one single modulation unite, which can improve receiver sensitivity too.更多还原