Semi-infinite One-dimensional Photonic Crystal Research Articles

Tunable terahertz Bloch surface waves in one-dimensional photonic crystals with a Dirac semimetal cap layer

The dispersion relation and localization of surface waves in semi-infinite one-dimensional photonic crystals in the presence of Dirac semimetal as a cap layer are theoretically and numerically investigated, using the transfer matrix method at terahertz band. It is demonstrated that the frequency and localization of surface waves can be tuned by changing the cap layer's Fermi energy for both transverse electric and transverse magnetic polarizations. The numerical results show that the dispersion relation of surface waves and consequently their localization are more sensitive to changes in Fermi energy. Therefore, the surface states with the desired localization can be achieved. In addition, the effect of the cap layer's thickness and the arrangement of the photonic crystal layers on surface waves are investigated. The results show that these parameters have considerable effect on modification of surface waves.

Controlled switching of the optical surface waves in one-dimensional photonic crystals containing left-handed materials in the presence of a chiral metamaterial as a cap layer

We theoretically investigated the localization and switching properties of surface waves that appear at the interface between the homogeneous medium and a semi-infinite one-dimensional photonic crystal in the presence of chiral metamaterial as a cap layer, using the transfer matrix method. The one-dimensional photonic crystal is made of alternating layers of right-handed and dispersive left-handed materials, and both forward and backward surface waves were appeared in this structure. It was demonstrated that the chirality parameter of the cap layer plays a significant role in tuning the type (changing forward to backward and vice versa) and localization of surface waves with transverse electric polarization. We believe that our results provide a useful way for a deeper understanding of the properties of surface waves in photonic devices and metamaterial systems.

On the relation between the propagation constant of Bloch surface waves and the thickness of the upper layer of a photonic crystal

We consider the derivation of a dispersion relation of Bloch surface waves supported by interfaces between a semi-infinite one-dimensional photonic crystal and a homogeneous medium. From the derived dispersion relation, we obtain an explicit analytical expression that defines the relationship between the propagation constant and the thickness of the upper layer of the photonic crystal.

One-way transmission through merging of magnetic defect state and optical Tamm states

Abstracts To achieve a new type of one-way transmission, we design a semi-infinite one-dimensional photonic crystal (PC) coated with a magneto-optical (MO) material film. In the surface of this structure there are merging states of MO defect state and optical Tamm state (OTS). We deduce the dispersion equation of the merging states basing on the Bloch theorem of periodic structures and transfer matrix method. There are two nonreciprocal dispersion curves of the merging states for k x and − k x , respectively. The positions of the merging states can be adjusted through changing the thickness of the MO film. With the use of the attenuated total reflection (ATR) prism coupling, we consider a one-way transmission based on a finite one-dimensional PC structure. The simulations by using a finite element method demonstrate the one-way transmission results.

Tamm states of one-dimensional photonic crystal based on surface defect

PDF HTML阅读 XML下载 导出引用 引用提醒 基于表面缺陷一维光子晶体Tamm态的研究 DOI: 作者: 作者单位: 江苏大学计算机科学与通信工程学院 镇江,江苏大学计算机科学与通信工程学院 镇江,宁波大学物理系 宁波 作者简介: 通讯作者: 中图分类号: 基金项目: 《应用非线性科学与技术》浙江省重中之重学科开放基金(No.xkz11012)； Tamm states of one-dimensional photonic crystal based on surface defect Author: Affiliation: School of Computer Science and Telecommunication Engineering,School of Computer Science and Telecommunication Engineering,Department of Physics, Ningbo University Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:基于周期结构的布洛赫原理，从电磁场理论出发，用解析和数值的方法系统地研究了基于表面缺陷的半无限一维光子晶体Tamm态的形成条件，模式特征以及与无缺陷Tamm态之间的关系.对TE波，缺陷Tamm态的频率范围向高低两个方向扩大；而对TM波，缺陷Tamm态的频率范围只向高频扩大, 而低频范围减小.缺陷折射率较大时, 缺陷Tamm态的色散曲线近似直线, 其群速度大小也近似等于光在单层缺陷里的传播速度. 通过调节缺陷层的折射率或者厚度可以方便地把缺陷Tamm态的频率设计到需要的范围. Abstract:Based on the Bloch theory of periodic structure, the Tamm states of semi-infinite one-dimensional photonic crystal with surface defect (the defect Tamm states) were studied through analytical and numerical methods. The forming condition and field properties of the defect Tamm states was obtained. The properties of the defect Tamm states and the Tamm states without defect was also compared. For TE wave, the frequency range of defect Tamm state is enlarged to both high frequency and low frequency; for TM wave, the frequency range of defect Tamm state is only enlarged to high frequency, but is narrowed in low frequency. For large refraction index of defect material, the dispersion curve of Tamm state is close to a straight line and the group velocity is close to that light velocity in the single defect layer. The frequency of the defect Tamm state can be adjusted into our needed range by changing the refraction index or thickness of the defect layer. 参考文献 相似文献 引证文献

Dispersion properties of nonlinear surface waves in one-dimensional photonic crystals with a nonlinear self-defocusing cap layer of left-handed metamaterial

In this paper we investigate analytically the localized surface waves (SWs) based on the first integral of the nonlinear Helmholtz wave equation in a semi-infinite one-dimensional photonic crystal (1DPC) truncated with a self-defocusing nonlinear cap layer of a left-handed material (LHM). The intensity-dependent properties of nonlinear SWs at the interface between air background and 1DPC are of two types: conventional photonic crystal (PC) and left-handed PC (made of alternate LHM and right-handed material) ones. It is shown that there are unusual SWs with different peculiarities for these two types of PC. To confirm our results, we also compared the results obtained by this method and the alternative method based on δ-function, for the structure with a very thin nonlinear cap layer.

Controlled switching of surface waves in 1D photonic crystals by a thin nonlinear cap layer

In this paper, we investigate the electromagnetic surface waves localized at the interface of the homogeneous dielectric medium and a semi-infinite one-dimensional photonic crystal (1D PC), theoretically. The semi-infinite 1D PC is made of alternative layers of left-handed (LH) and right-handed (RH) materials in the presence of a thin nonlinear cap layer. We consider magnetic permeability and electric permittivity of LH layers being dispersive and non-dispersive. We used an analytical direct matching procedure within the Kronig-Penny model to analyze the dispersion behavior of surface waves with controllable localization. It is shown that the thin nonlinear cap layer acts as a tool to change the backward surface waves to forward ones and vice versa and it plays an important role on the localization of them. Also we show that when the LH layers are chosen dispersive, negative dispersion of surface waves are obtained in a wide range of radiation angle and frequency, and we propose an approach to calculate the applied electric field intensity that leads to switching of surface waves from backward to forward and creating a surface mode with maximum localization.

Electromagnetic surface modes in one-dimensional photonic crystals with dispersive metamaterials

We study the electromagnetic surface modes supported by the interface between semi-infinite one-dimensional photonic crystals composed of dispersive metamaterials and a homogeneous medium in the presence of the cap layer. A new type of surface mode is found in such structure, and these surface modes can exhibit strong resonance at the first period of the photonic crystal. These resonant surface modes originate from the material dispersion. Another type of surface mode with structural resonance can appear in the thick cap layer. The influences of physical parameters of the structure on the surface modes have also been investigated.

Analysis of Bloch-surface-wave assisted diffraction-based biosensors

A systematic study of Bloch surface wave (BSW) properties and applications in diffraction-based biosensors is presented. The design of such devices starts with the calculation of the BSW dispersion relation for a semi-infinite one-dimensional photonic crystal. We propose an approach in which polarization and 1DPC termination effects are simply described. Since in a realistic device the number of periods is limited, we investigate the issues arising from finite size effects and the choice of a structure substrate. Diffraction efficiency is studied as a function index contrast, multilayer termination, grating thickness, and number of periods. Numerical examples for Si/SiO2 and a-Si1−xNx:H periodic dielectric stacks are presented, showing that BSW can be exploited for the realization of efficient diffraction-based biosensors from the infrared to the visible range.

Reflectivity of semi-infinite one-dimensional photonic crystal composed of alternate layers of ordinary material and negative refraction material

The reflection on the semi-infinite periodic one-dimensional photonic crystal composed of alternate layers of ordinary material and negative refraction material is investigated. We find that the reflectivity is exactly equal to 1 in the forbidden frequency gap, and in the pass band, it averages out the rapid fluctuation of reflection of the finite structure. When the optical thickness of both ordinary material and negative refraction material are in opposite sign, there will be a zero-n band gap. We analytically prove that the zero-n band gap is insensitive to incident angle and polarization. It is also anticipated that the zero-n band gap is invariant with the scaling of lattice constant.

Nonlinear surface waves in one-dimensional photonic crystals containing left-handed metamaterials

The nonlinear TE-polarized surface waves localized at the interface between a nonlinear uniform material and a semi-infinite one-dimensional photonic crystal are investigated. We assume that the nonlinear material is right handed and the photonic crystal is made of alternate left-handed metamaterial and right-handed material. We study the intensity-dependent properties of the nonlinear surface waves for both self-focusing and defocusing Kerr-like nonlinearity. Unlike the linear regime, it is shown that in the case of self-focusing nonlinearity the dispersion curve has two branches corresponding to two types of surface mode structures (one structure with a hump at the interface and the other one with two humps). While, in the case of defocusing nonlinearity the dispersion curve has a single branch. We also show that the existence region of the surface waves is intensity dependent (independent) in the case of self-focusing (defocusing) nonlinear regime and the presence of left-handed materials and nonlinear medium provides a possibility for forward or backward waves selection in the given structure by adjusting the intensity parameter at the interface.

Backward surface electromagnetic waves in semi-infinite one-dimensional photonic crystals containing left-handed materials

We study the electromagnetic surface waves localized at an interface separating a homogeneous dielectric medium and a semi-infinite one-dimensional photonic crystal made of alternative left-handed metamaterial and right-handed material. An analytical direct matching procedure within the Kronig-Penney model was applied to analyze the dispersion properties of the localized surface states. We show that the presence of metamaterial in the photonic crystal structure can support the surface waves with a backward energy flow and allows a flexible control of dispersion properties of the surface modes. The surface states can be either forward or backward waves depending on the physical parameters of the photonic crystal, physical parameters of the cap layer, the position of the surface plane, and incident angle of the incoming beam.

Surface Optical Waves in Semi-Infinite One-Dimensional Photonic Crystals Containing Alternating Layers of Positive and Negative Media

An analytical direct matching procedure within the Kronig-Penney model applied to analyze the dispersion behavior of the localized surface states supported in the surface of a semiinfinite one-dimensional photonic crystals truncated with air. The photonic crystal containing alternating layers of positive and negative media. In the case of the conventional indices, as the incident light changes from normal to oblique incidence, the surface modes shifts into higher frequencies. For this reason, the phenomenon of photonic band gap has been used only under a narrow range of frequencies of light incident at a particular angle or in a particular angular range. We have showed that by choosing some proper value for the PC parameters, zero and negative dispersion of surface modes emerge in a large range of k|| , and, due to the different nature of the band structure the surface modes are more localized compared to those appeared in the conventional PC.

Surface Optical Waves in Semi-Infinite One-Dimensional Photonic Crystals Containing Alternating Layers of Positive and Negative Media with a Cap Layer

An analytical direct matching procedure within the Kronig–Penney model was applied to analyze the dispersion behavior of the localized surface states supported at the surface of a semi-infinite one-dimensional photonic crystals truncated with air or a cap layer. The photonic crystals contain alternating layers of positive and negative media. The present study demonstrates that by choosing some proper value for the photonic crystal parameters, zero and negative dispersion of surface modes emerge in a large range of parallel wave vector. New forward and backward surface waves are introduced. Due to the different nature of the band structure the surface modes are more localized compared to those appearing in the conventional photonic crystals.

Surface optical waves in semi-infinite one-dimensional photonic crystals with a thin nonlinear cap layer

An analytical direct matching procedure within the Kronig–Penney model was applied to analyse the dispersion behavior of the localized surface states supported in the surface of a semi-infinite one-dimensional photonic crystals truncated with a thin nonlinear cap layer. We find that the surface states are very sensitive to the nonlinearity of cap layer on the surface.

Systematic design of antireflection coating for semi-infinite one-dimensional photonic crystals using Bloch wave expansion

We present a systematic method for designing a perfect antireflection coating (ARC) for a semi-infinite one-dimensional (1D) photonic crystal (PC) with an arbitrary unit cell. We use Bloch wave expansion and time reversal symmetry, which leads exactly to analytic formulas of structural parameters for the ARC and renormalized Fresnel coefficients of the PC. Surface immittance (admittance and impedance) matching plays an essential role in designing the ARCs of 1D PCs, which is shown together with a practical example.