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1.
由于光子晶体的禁带特性具有重要的应用,基于电磁波传输理论,应用MATLAB数值仿真二维正方晶格光子晶体TE模第一带隙特性,数值计算了介电常数变化、填充率变化对第一带隙宽度及形成带隙个数的影响,结果得到随着介电常数的增加第一带隙宽度增加,随着填充率的增加,第一带隙宽度逐渐减小。研究结论为光子晶体器件的制作提供参考。  相似文献   

2.
代洪霞  刘启能 《激光技术》2013,37(3):338-341
为了研究1维方形掺杂光子晶体波导中缺陷模的色散,采用特征矩阵的方法研究了1维方形掺杂光子晶体波导中TE波和TM波缺陷模的变化特征,得到了TE波和TM波的缺陷模随色散强度、色散厚度变化的结果。结果表明,色散强度和色散厚度都会对1维方形掺杂光子晶体波导中TE波和TM波的缺陷模产生明显的影响;利用TE波和TM波的缺陷模随色散强度、色散厚度的变化规律,可以有效地实现对1维方形掺杂光子晶体波导中TE波和TM波各传输模式的有效控制。  相似文献   

3.
利用全矢量有限元法,分析了方形空芯光子晶体光纤的色散特性、纤芯内的能量分布和有效模面积.结果表明,方形空芯光子晶体光纤在1.67~1.81 μm范围内具有较平坦的色散特性,较高的能量分布和较大的有效模面积,为进一步设计具有平坦色散和大模场面积的方形空芯光子晶体光纤提供了理论依据和参考.  相似文献   

4.
太赫兹波在二维正方晶格光子晶体中的传播特性   总被引:1,自引:0,他引:1  
本文用平面波展开法研究了太赫兹波(THz)在二维正方晶格光子晶体中的传播特性。分析了晶格常数为a=0.1mm的正方晶格介质柱二维光子晶体,在0~1.8THz频段范围内,通过数值计算,发现当介质圆柱半径r=0.2a时,E偏振出现最大绝对光子带隙,带隙位于0.283-0.400THz,带隙宽度为0.117THz,相应的带隙波长范围为84.9μm至120μm,处于THz波段,并分析了随着相对介电常数差值的增大出现的TM带隙宽度增大。研究结果为THz器件的开发提供了理论依据。  相似文献   

5.
A novel optical waveguide exhibiting a layered core region is proposed. Owing to the original design of the core stack and form birefringence in the multilayer, a waveguide supporting both TE and TM lowest-order modes with high confinement has been obtained. It has been designed, fabricated, and characterized and presents a modal birefringence greater than 0.01, which is in good agreement with the calculated values.  相似文献   

6.
Linewidth and small-signal modulation response measurements are reported for room-temperature-operating microcavity two-dimensional photonic crystal lasers. The measured optical linewidth versus the output power was found to saturate at values on the order of 1 GHz. The modulation bandwidth for these low-power lasers was demonstrated to be on the order of 10 GHz.  相似文献   

7.
By employing 2D plane wave expansion (PWE) and finite difference time domain (FDTD) methods, a photonic crystal waveguide (PCW) based on the compound square lattice structure is presented. Band-gap can be observed for TM polarization and compared with the simple lattice structure based on the same material the band-gap is increased by 62.7%. By optimizing the parameters we get the PCW with the propagation only near the wavelength of 1.55 μm and a flat group index curve in a wide wavelength range of 40 nm. And the group velocity dispersion compensation can be realized by the structure optimization. The results provide a reference for the study and application ofphotonic crystal waveguide based on the compound lattice structure.  相似文献   

8.
We investigate in detail control methods of polarization mode in a two-dimensional square-lattice photonic crystal laser. In order to control the polarization mode using the square lattice, we investigate the eigenmode of the electromagnetic field against the possible symmetry groups of a square lattice. Both the electromagnetic field distributions of lasing oscillation mode and the band diagram are significantly influenced by the symmetry groups. In the case of the square lattice structure, symmetries "p1", "pm", "p2", and "pmm" are suitable for obtaining the unidirectional polarization mode. Among these symmetry groups, the symmetry group "pmm" is especially interesting considering the simplicity of the eigenmode of the electromagnetic field. In order to obtain the symmetry group "pmm", we deform the unit cell structure of a square lattice from circular to elliptical and investigate the properties of symmetry group "pmm" in detail. The elliptical ratio of the unit cell structure can modify the coupling balance of a lightwave propagating in two perpendicular in-plane directions and can control the eigen energy of each band edge.  相似文献   

9.
Quantum dot photonic crystal lasers   总被引:1,自引:0,他引:1  
Coupled cavity designs on two-dimensional square lattice photonic crystal slabs were used to demonstrate optically pumped indium arsenide quantum dot photonic crystal lasers at room temperature. Threshold pump powers of 120 and 370 μW were observed for coupled cavities including two and four defect cavities defined in optimised photonic crystals  相似文献   

10.
构建了一种金属-绝缘体-半导体混合表面等离子体结构,基于时域有限差分法验证了该结构在归一化频率0.243~0.271 (a/λ) 范围内具有明显的TM模式带隙。在二维光子晶体层移除或改变中间行空气孔半径构成线缺陷,形成混合波导结构1和2。分析表明,入射光频率位于带隙内的光子能量被很好的局域在低折射率层中,且只能沿线缺陷传输。当入射波长为1550nm时,两种波导的传输距离分别为18.41μm和15.70μm,群速度极值分别为0.186c和0.166c,品质因数FoM达到384.74和1042.50。此波导能通过光子晶体层的线缺陷控制低折射率层SPP的传输路径,为波导器件的研究提供了有效的理论基础和依据。  相似文献   

11.
为了研究2维正方晶格光子晶体的完全带隙特性,采用平面波展开方法模拟了两种结构2维光子晶体,在固定光子晶体周期常数a的前提下,研究了2维正方晶格光子晶体的完全禁带随柱半径和折射率的变化规律。结果表明,以空气为背景的锗介质柱组成的光子晶体,随着半径的增大,完全带隙宽度先增大后减小最后消失,填充比为38.3%时,同时增大介质柱的介电常数,在介质柱折射率为4.2处,完全带隙最大,带宽是0.02754(ωa/(2πc));以锗为背景的空气柱组成的光子晶体,光子禁带对应的无量纲频率随半径的增大而增大,填充比为48.3%时,同时增大背景介质的介电常数,出现多个完全带隙,在背景折射率为6.2处,完全禁带最大,带宽为0.02922(ωa/(2πc))。光子晶体带隙的频谱响应也表明了完全带隙的范围。这为大带隙2维正方晶格光子晶体的设计和制备提供了依据。  相似文献   

12.
Multimode interference-based photonic crystal waveguide power splitter   总被引:2,自引:0,他引:2  
A compact power splitter based on the multimode interference (MMI) effect in photonic crystal waveguides is designed and analyzed. The device size reduction compared with the conventional MMI power splitter can be attributed to the large dispersion of the photonic crystal waveguides. The Massachusetts Institute of Technology Photonic-Bands code is used to calculate the band structures of photonic crystal waveguides. The finite-difference time-domain method is adopted to simulate the relevant structures.  相似文献   

13.
Group delay and chromatic dispersion of a Fabry-Perot resonator embedded in a photonic crystal waveguide have been directly measured at 1.55 /spl mu/m wavelength using the phase-shift technique. The photonic crystal waveguide resonator was fabricated in an InGaAsP/InP heterostructure and was designed to show a channel spacing of 100 GHz. Group velocity dispersion up to 250 ps/nm was observed.  相似文献   

14.
Optimal design for one-dimensional photonic crystal waveguide   总被引:1,自引:0,他引:1  
This paper proposes a logical method to design and optimize one-dimensional photonic crystal waveguides (PCWs). The logic is deduced from practical issues such as the fabrication of the waveguide structures and the subsequent optical coupling to other conventional waveguides. It is found that the individual layer thickness of an optimally designed PCW is exactly one quarter of the projection of the effective wavelength in the direction perpendicular to the layer plane. The paper also describes a handy way of finding the thickness of the central guiding layer of a symmetric waveguide. In order to demonstrate that the proposed logic and schemes are indeed functional, detailed numerical calculations are provided for a model PCW structure composed of a GaAs-AlAs-oxide system and an air-guiding layer.  相似文献   

15.
文中采用有限时域差分(FDTD)法研究了ZnO随机介质与光子晶体波导相结合的微型激光器的辐射特性和频谱特性,用平面波展开法分析了光子晶体能带特性。数值研究结果表明:由于光与随机介质相互作用,使得光在该微型激光器中放大,损耗减小,存在较长滞留时间,同时随机介质局域光的能力变强,激光的阈值降低,而且含四方格子结构光子晶体的激光器具有良好的激光特性和调制作用。该新型器件的设计与研究将为研制可嵌入集成光子芯片的、低阈值的微型激光器提供理论基础。  相似文献   

16.
Highly birefringent index-guiding photonic crystal fibers   总被引:10,自引:0,他引:10  
Photonic crystal fibers (PCFs) offer new possibilities of realizing highly birefringent fibers due to a higher intrinsic index contrast compared to conventional fibers. In this letter, we analyze theoretically the levels of birefringence that can be expected using relatively simple PCF designs. While extremely high degrees of birefringence may be obtained for the fibers, we demonstrate that careful design with respect to multimode behavior must be performed. We further discuss the cutoff properties of birefringent PCFs and present experimental results in agreement with theoretical predictions on both single- and multimode behavior and on levels of birefringence  相似文献   

17.
Room-temperature operation of two-dimensional photonic crystal lasers optically pumped by a vertical-cavity surface-emitting laser emitting at 860 nm is reported. The photonic crystal membrane is surrounded by air on both sides and consists of four compressively strained quantum wells as the active region. The incident threshold pump power of an approximately 2.6-μm-diameter hexagonal defect cavity laser operating at 1.6 μm is 2.4 mW  相似文献   

18.
We present results of tunable GaInNAs lasers with photonic crystal (PhQ mirrors, fabricated from GaAs-AlGaAs layers with a double GaInNAs quantum well emitting at IR wavelength. The devices are realized as ridge waveguide lasers with two coupled segments and a total length between 240 and 580 pm. PhC blocks with different thicknesses are used for the back and front mirror as well as for the intermediate reflector between the two segments. The lasers have threshold currents around 20 mA and output powers up to 6 mW. Tuning of the laser emission over 30 nm is achieved by a variation of the currents injected into the two segments.  相似文献   

19.
基于平面波展开法,以长方格子光子晶体带隙特性为研究对象,改变长方格子空气圆柱半轴a和b的大小,得到当a=b时形成较宽的光子带隙,随着b的增大,光子带隙逐渐减小.改变构成长方格子光子晶体基底的材料,得到Ge构成基底时形成较宽的光子带隙.研究结果为光子晶体器件的制作提供参考.  相似文献   

20.
为了对折射率型1维光子晶体缺陷波导中的光传输进行有效数值模拟,采用此类型波导的厄米-高斯函数展开方法进行了研究。首先给出了计算方法的详细理论推导,然后利用该方法计算了偏振态不同、结构参量不同的情况下波导本征模式的色散关系、模场空间分布、能量控制因子及等效折射率。结果表明,1维光子晶体缺陷波导与阶跃平面光波导主要差别在于高阶模式,且可通过调节1维光子晶体的结构参量来有效调控高阶模式的传输。  相似文献   

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