声光子晶体结构中的波传播及声光耦合作用研究

发布时间：2017-12-31 20:10

本文关键词：声光子晶体结构中的波传播及声光耦合作用研究　出处：《北京交通大学》2017年博士论文　论文类型：学位论文

【摘要】：声光子晶体是一种同时具有光子和声子带隙的周期性结构。声光子晶体为同时控制光波和声波的传播提供了一个系统的平台,并在光学、声学及声光多功能器件、腔光力学等领域展现了十分广阔的应用前景。本文利用有限元方法,针对声光子晶体双重带隙的调控、体模式和边界模式的光波和声波传播特性、谐振腔结构中的声光耦合效应以及器件设计等若干问题进行了研究。主要内容和结果包括:1.提出了一类具有纹理拓扑形式的二维声光子晶体结构,该类结构可以同时产生光子和声子体波带隙;分析了二维体系下光和声的体波及表面波模式的波动特性;设计了表面模式谐振腔和含空气狭缝的谐振腔,并分析了上述结构中的声光耦合效应。结果表明:正方晶格和蜂窝晶格有利于同时产生较宽的光子和声子体波带隙;针对不同的表面结构形式,声表面波可表现为耦合共振模式或局域共振模式;通过改变表面结构可以有效地调控光和声的表面波模式,且容易同时获得光和声的表面波模式(或带隙);若声学谐振腔模式具有偶对称性,且光学和声学谐振腔模式波场的重合程度高,则声光相互作用增强;含空气狭缝的谐振腔由于光场和声场间的重合程度较高,比表面模式谐振腔表现出更强的声光耦合作用。2.在具有纹理拓扑形式的二维声光子晶体基础上,提出了同时具有光子和声子带隙的声光子晶体板结构;分析了光和声的板波及侧表面波模式的波动特性;设计了含空气狭缝的声光子晶体板谐振腔,并分析了谐振腔中的声光耦合效应。结果表明·这类声光子晶体板可以在较广的几何参数范围内同时产生较宽的光子偶模(或奇模)带隙和声子带隙;通过改变侧表面结构可以有效地调控光和声的侧表面波模式,且容易同时获得光和声的侧表面波模式或带隙;含空气狭缝的谐振腔,由于其光场和声场高度重合,因此表现出很强的声光耦合作用,且移动界面效应在其中占主导地位。3.提出了两类具有纹理拓扑形式的三维声光子晶体结构,这两类结构均可以同时产生光子和声子带隙,其中第一类模型散射体位于晶格格点并由细圆柱相连接,第二类模型为在硅基体中挖球形孔而形成的开孔式周期结构;分析了该体系中光和声的体波、表面波和棱波模式的波动特性;讨论了缺陷的几何参数对点缺陷和线缺陷的影响。结果表明:第一类模型利于同时产生较宽的光子和声子体波带隙,但第二类模型利于在实验室加工制备;通过改变表面结构可以有效地调控光和声的表面波模式,其中同时获得光和声的表面波模式相对容易,而同时获得光和声的表面波带隙则相对困难;通过改变棱边结构可以有效地调控光和声的棱波模式,由于获得光棱波模式相对困难,为了同时获得光和声的棱波模式在结构设计中应以获得光棱波模式为前提,并在此基础上调节棱边结构;在声光子晶体的缺陷态下光场和声场均呈现高度局域化,且通过改变缺陷的几何参数可以有效地调控缺陷态。4.设计了基于表面波模式的声光子晶体液体传感器及声光子晶体单向传输结构。结果表明:声光子晶体传感器可以同时检测液体的光学折射率和声速,且具有较高的灵敏度,与传统纯光子或声子晶体传感器相比其优势在于多物理参数的同时检测;与体波器件相比表面波器件中的表面波更容易激励和接收。对于单向传输结构,在格栅衍射和方向带隙共同作用下,方向带隙频率范围内光波和声波均出现了单向传输效应;在极化模式转换和模式带隙共同作用下,模式带隙频率范围内的声波会出现单向传输效应。总之,本文的研究结果表明,无论是二维还是三维体系下,为了同时获得较宽的光子和声子带隙,可以令声光子晶体具有如下的结构拓扑形式:电介质柱或球位于晶格节点且由较细的电介质体相连接。体波带隙是产生表面波模式及带隙的前提,而表面波带隙是产生棱波模式的前提,因此获得较宽的体波带隙对于边界模式的调控和应用至关重要。
[Abstract]:The sound of photonic crystal is a periodic structure with photonic and phononic band gaps. The system provides a platform for communication and control the sound of photonic crystal light waves and sound waves, and in optical, acoustic and acousto-optic multifunctional devices, optical mechanical fields show a very broad application prospect. This paper Co. finite element method, the regulation for the acoustic dual band gap photonic crystal, model and boundary model of wave and acoustic wave propagation characteristics, some problems of the coupling effect of acoustooptic cavity structure and device design are studied. The main contents and results include: 1. propose a texture with the topology of two-dimensional acoustic photonic crystal the structure, the structure can simultaneously produce photon and phonon bulk band gap; analysis of the fluctuation characteristics of light and sound wave surface wave mode two-dimensional system; design of surface mode resonator and containing The air slit cavity, and analyzes the structure of the acousto-optic coupling effect. The results showed that: Affirmative lattice and honeycomb lattice is conducive to simultaneously produce wide photonic and phononic band gaps for the body; the surface structure of different forms and manifestations of acoustic surface wave coupling resonance mode or local resonance mode by changing the surface structure; can effectively control the surface wave mode of light and sound, and also easy to obtain the surface wave mode of light and sound (or band gap); if the acoustic resonator mode has dual symmetry, and the optical and acoustic resonator mode wave field coincides with the high degree of enhancement of acousto-optic interaction; containing air slit cavity due to light field and the field between the coincidence degree is higher, than the surface mode resonant cavity showed stronger acousto-optic coupling.2. in two-dimensional photonic crystal with sound based on the topology of the texture, put forward at the same time A photonic crystal slab photonic and phononic band gap; analyzed the fluctuation characteristics of light and sound wave plate side surface wave mode; the sound design of photonic crystal slab cavity with air slits, and analyzed the coupling effect of acoustooptic resonant cavity. The results show that, this kind of sound photonic crystal plates can be produced at the same time photon even mode wide geometrical parameters in a wide range (or odd) band gap and phonon band gap; by changing the side surface structure can effectively control the side surface modes of light and sound, and also easy to get light and sound wave mode or side band gap; cavity with air slits, because the light field and sound field of a high degree of overlap, thus showing acousto-optic coupling is very strong, and the mobile interface effect in which the dominant.3. proposed two kinds of texture topological form of 3-D photonic crystal structure, these two kinds of structure can be At the same time to produce photonic and phononic band gap, in which the first position in lattice scattering model and connected by thin cylinder, hole type periodic structure of the second kind of model is digging spherical pores in the silicon substrate and the formation; analysis of body waves of light and sound in the system, the fluctuation characteristics of surface wave and edge wave mode the effect of geometrical parameters; defect of point and line defects are discussed. The results show that the first model can also generate wider photonic band gap and phonon body, but the second model in the laboratory for preparation and processing; by changing the surface structure can effectively control the surface wave mode of light and sound, which at the same time to obtain the surface wave mode of light and sound is relatively easy, while the surface wave band gap of light and sound is relatively difficult; by changing the edge structure can effectively control the light and sound of the edge wave mode, due to the prism wave mode The type is relatively difficult, in order to obtain both the light and sound edge wave mode in the structure design should be to obtain light edge wave mode as the premise, and on the basis of adjusting the edge structure; in the defect states of photonic crystal optical sound field and sound field are highly localized, and by changing the geometric parameters of the defects can be effectively controlled.4. designed the defect states of photonic crystal liquid acoustic sensor and acoustic surface wave mode photonic crystal unidirectional transmission structure based on photonic crystals. The results show that the acoustic sensor can detect the optical refractive index and velocity of the liquid, and has high detection sensitivity, compared with the traditional pure photon or phonon crystal sensor has the advantages of multiple physical parameters at the same time compared with the body surface wave device; in SAW devices more easily. For excitation and reception of unidirectional transmission structure, in the direction of the band gap and the diffraction grating together with The direction of the band gap, the frequency range of light waves and sound waves appeared in the unidirectional transmission effect; polarization mode conversion mode and bandgap together, with acoustic frequency range of the gap will appear one-way transmission effect. In short, the results of this study show that both the two-dimensional three-dimensional system is also at the same time, in order to get more the width of the photonic and phononic band gap, can make the sound of photonic crystal structure with topological form as follows: dielectric column or ball in lattice nodes and is connected by a dielectric body thin body. The band gap is the surface wave mode and premise of band gap, and the surface wave band gap is a precondition to edge wave mode, thus obtained bulk band gap is wide in the regulation and application of boundary model is very important.

【学位授予单位】：北京交通大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：O734

【引证文献】