【作者】 汪舟；

【导师】 孙军强；

【作者基本信息】 华中科技大学 ， 物理电子学， 2011， 硕士

【摘要】 微环谐振腔由于具有体积小,结构简单,集成度高,插入损耗小等优点,在光集成器件中应用十分广泛。微环谐振腔在激光器中,主要是提供对纵模的选择作用。如果使用两个微环进行级联,由于游标效应,可以使自由光谱范围（FSR）增大。太赫兹（THz）辐射由于所处的频谱位置的特殊性,在许多方面有广阔的应用前景。本论文设计的基于微环谐振腔结构的半导体激光器可以产生双波长单纵模的激光,用于拍频产生太赫兹信号。本论文的主要研究内容如下:（1）介绍了THz辐射的研究背景及意义,介绍了光学微环谐振腔在光集成器件中的应用,提出了一种新的基于双微环结构的双波长半导体激光器,并可以用来拍频产生THz信号。（2）对矩形波导的模场分布特性进行了研究,通过对其特征方程的求解,模拟了E_mn^y模的场分布。当直波导尺寸较大时,既有基模又有高阶模。当直波导尺寸比较小时,只存在基模。接着分析了弯曲波导的模场分布特性及波导尺寸对其模场的影响。（3）分析了微环谐振条件,以微环与直波导侧向耦合为例,分析了其耦合系数与传播距离的关系,振幅耦合比率与波导尺寸和波长的关系,并进行了模拟仿真。研究了微环内相向传播光方向控制的方法。（4）研究了上下载型微环和级联微环的滤波特性,在此基础上,设计了一种新型的双波长单纵模可调谐半导体激光器,建立了该激光器的理论模型,研究了其阈值特性,动态特性和稳态特性。（5）通过对不同制作材料进行比较,最终选择InGaAsP/InP材料制作该激光器,研究了InGaAsP/InP材料无源/有源微环侧向耦合结构的加工工艺,研究了无源/有源混合结构的加工工艺,并对本论文提到的新型激光器的加工工艺进行了设计。更多还原

【Abstract】 With the advantages of small volume, simple structure, high integration density and low insertion loss, microring resonators are widely used in optical integrated devices. Microring resonator acts mainly as a longitudinal mode selector in a laser. If two microrings are cascaded, free spectral range （FSR） can be extended as a result of vernier effect. THz radiation has broad application prospects in lots of fields owing to its special position in the frequency spectrum. In this thesis, a semiconductor laser based on microring resonators is designed. The laser can emit dual-wavelength single longitudinal mode light for generating THz signals by the way of frequency beating. The major research achievements are as the following:（1） The research background and significance of THz radiation is introduced. Applications of microring resonators are presented. A novel dual-wavelength semiconductor laser based on double ring structure is proposed, which can be used to generate THz signals.（2） Mode distribution in stripe waveguides is researched. Mode distribution of E_mn^y mode is simulated by solving characteristic equations. Both basic mode and high order modes exist when the size of the stripe waveguide is large, and only basic mode exists when the size of the stripe waveguide is small. Mode distribution in a bent waveguide, and the effect of the size of the bent waveguide to the distribution is analyzed.（3） The resonance condition for a microring is analyzed. To take lateral coupled microring and bus waveguide for an example, the relation between the coupling efficiency and the propagation distance and relation between the coupling ratio and the size of the waveguide is analyzed and simulated. The way for directional control of counter propagating lights in microrings is researched.（4） Filtering characteristics of an add/drop ring and cascaded rings are researched, based on which a novel dual-wavelength single longitudinal mode tunable semiconductor laser is presented. Theoretical model of the designed laser is presented and threshold characteristics, dynamic characteristics and stable state characteristics of it is researched.（5） Different types of material are compared, and InGaAsP/InP material is finally chosen to fabricate the laser. Fabrication of lateral coupled passive/active microring resonators and mixed construction with passive parts and active parts is researched, and the fabrication method of the designed laser is proposed.更多还原