Investigation of Photonic Band Gap in Si-Based One-Dimensional Photonic Crystal

A one-dimensional silicon based photonic crystal with nonlinear defect layers is examined. The linear and nonlinear optical properties are analyzed. The transmission spectrum was obtained by applying the optical transfer matrix formalism to the photonic crystal. The various transmittance peaks obtained with the defect layers are investigated. The nature of the transmittance peak is analyzed with the number of defect layers.

Synthesis and Crystal Structure of 1-(4-Fluorophenyl)-2-hexylthiobenzo[4,5]-furo[3,2-d]-1,2,4-triazolo[1,5-a]pyrimidin-5(1H)-one

The crystal structure of the title compound 1-（4-fluorophenyl） -2-hexylthio-benzo [4,5]furo[3,2-d]-1,2,4-triazolo[1,5-a]pyrimidin-5（1H） -one（C23H21FN4O2S,Mr = 436.5） has been prepared and determined by single-crystal X-ray diffraction. The crystal is of monoclinic,space group P21/n with a = 13.9854（3） ,b = 17.2678（4） ,c = 18.1828（5）A,β = 99.364（2） °,V = 4332.58（18） A^3,Z = 4,Dc = 1.338,F（000） =1824,μ = 0.185 mm^-1,MoKa radiation（λ = 0.71073） ,R = 0.0538 and wR = 0.1162 for 4728 observed reflections with I 〉 2σ（I） . X-ray diffraction analysis reveals the fused rings of benzo[4,5]furo[3,2-d]-1,2,4-triazolo[1,5-a] pyrimidin-5（1H） -one system are nearly coplanar. The crystal packing is mainly stabilized by weak intermolecular C-H···O hydrogen bond and π-π interactions.

Synthesis and Crystal Structure of 1-D Chain Copper(Ⅱ) Complex: [Cu(L)Cl_2]_n (L=2,5-Di-2-pyridyl-1,3,4-oxodiazole)

The title complex, [Cu(L)Cl2]n (L = 2,5-di-2-pyridyl-1,3,4-oxodiazole) 1, has been obtained from the reaction of 3,6-di-2-pyridyl-1,2,4,5-tetrazine (bptz) and CuCl2?H2O in a mixture solvent of CH3CN and CH2Cl2 (L is generated from the metal-assisted hydrolysis reaction of bptz) and structurally characterized. It crystallizes in space group C2/c of monoclinic system with cell parameters: a = 9.812(2), b = 12.679(3), c = 11.111(2) ? b = 103.92(3)? V = 1341.6(5) 3, Z = 4, Dc = 1.776 g/cm3, Mr = 358.66, F(000) = 716, ?= 2.024 mm1 and S = 1.004. The final R = 0.0346 and wR = 0.0938 for 1011 observed reflections with I > 2(I). The Cu(Ⅱ) ion is six-coordinated by four N atoms of two L ligands and two Cl ions in a distorted octahedral geometry. The ligand L acts as a bis-bidentate ligand to bridge the Cu(Ⅱ) ions, resulting in an infinite chain structure.

Synthesis and Crystal Structure of Ethyl 3-(4-Chlorophenyl)-3,4-dihydro-6-methyl-4-oxo-2-(pyrrolidin-1-yl)furo[2,3-d]pyrimidine-5-carboxylate

The crystal structure of the title compound ethyl 3-（4-chlorophenyl）-3,4-dihydro-6- methyl-4-oxo-2-（pyrrolidin-1-yl）furo[2,3-d]pyrimidine-5-carboxylate （C20H20ClN3O4, Mr= 401.84） has been prepared and determined by single-crystal X-ray diffraction. The crystal is of monoclinic, space group P21/n with a = 20.6215（9）, b = 8.5311（4）, c = 21.6886（9） A^°, β = 91.607（1）°, V = 3814.0（3）A^°^3, Z = 8, Dc = 1.400 g/cm^3, F（000） = 1680, μ = 0.233 mm^-1, R = 0.0718 and wR = 0.1545 for 6717 observed reflections with I 〉 2σ（I）. X-ray diffraction analysis reveals two crystallographically independent molecules in the asymmetric unit.

Hydrothermal Syntheses and Characterizations of Two One-dimensional Molybdenum 1,4-Butylenediphosphonates

The reaction of Ni（CH3COO）2-4H2O, Na2MoO4·H2O, MoO3, 1,10-phenanthroline and 1,4-butylenediphosphonic acid in distilled water at 180℃ for 72 h produced two new compounds： {[Ni（1,10-phen）3][Ni（1,10-phen）2（Mo6O18）（O3P（CH2）4PO3）]·6H2O}n 1 in 15% yield and {[Ni（1,10-phen）2（H2O）2] [Ni（1,10-phen）2 （H2O）（Mo5O15）（O3P（CH2）4PO3）]·6H2O} n 2 in 47% yield. 1 and 2 both feature {MonO3nO3P（CH2）4PO3}^4-（n=5, 6） 1-D anionic chain, which is further decorated and charge compensated by [Ni（1,10-phen）2]^2＋. 1 contains {Mo6O24P2} cluster constructed of three pairs of face-sharing {MoO6} octahedra linked through corner-sharing interaction. 2 exhibits the characteristic structure based on pentanuclear ring of comer- and edge-sharing {MoO6} octahedra capped by three oxygen atoms of {PO3} on each side. The thermogravimetric analyses and magnetic property of 2 were also studied.

Rapid and sensitive detection of urinary KIM-1 using fully printed photonic crystal microarrays

Urinary kidney injury molecule 1(uKIM-1)serves as a reliable marker for the early diagnosis of acute kidney injury(AKI).The rapid and facile detection of changes in uKIM-1 is essential for early AKI diagnosis,ultimately improving the prognosis of patients.In this study,we developed a fully printed photonic crystal-integrated microarray with photonic crystal-enhanced fluorescence properties,which can detect uKIM-1 levels at the point-of-care.We confirmed its efficacy in the early diagnosis of AKI using clinical urine specimens.Direct quantitative detection of uKIM-1 was achieved within 10 min.The lowest limit of detection is 8.75 pg·mL^(-1) with an accuracy of 94.2%.The diagnostic efficacy was validated using 86 clinical urine samples,highlighting the high sensitivity and stability of the photonic crystal microarray.Consequently,a facile and reliable immunoassay was designed and prepared for the rapid quantitative detection of uKIM-1,which is crucial for the early identification and convenient detection of AKI in hospital or community settings.Rapid,convenient,cost-effective,and long-term monitoring of changes in uKIM-1 levels can assist clinicians in making timely adjustments to treatment regimens,preventing the transition from AKI to chronic kidney disease(CKD),improving the quality of life of patients with AKI,and reducing healthcare costs.It highlights the advantages of utilizing urine samples as a noninvasive and easily accessible medium for early detection and monitoring of kidney-related conditions.

The Gain Properties of 1-D Active Photonic Crystal

The terminology 'ID frequency'(w ID) is proposed after analyzing the 1D active photonic crystal based on the transfer matrix method. The relationship between wID and the structure parameters of the photonic crystal is investigated.

椭圆偏振光在各向异性1维光子晶体中的传输

为了解决利用传统传输矩阵法计算在各向异性材料结构中任意极化态电磁波传播遇到的困难,设计含磁光材料缺陷层的1维光子晶体。通过把入射电磁波按左旋圆偏振和右旋圆偏振进行正交分解的方法,推导出适合各向异性材料和任意极化态入射电磁波的传输矩阵算法。结果表明,该算法可以确定1维层状结构透射波和反射波偏振态的变化。

基于光子晶体1×3谐振腔滤波器的研究

考虑到滤波器输入波导中入射电磁波和反射电磁波的相位差,通过CMT理论分析了不同设计情况下的工作性能,然后优化设计了光子晶体1×3谐振腔滤波器结构.用FDTD方法研究了滤波器工作特性,改变1×3谐振腔下侧调谐柱位置得到滤波器结构的96个不同通带峰值波长平均正规化传输率为89.6%,相邻峰值波长平均间隔为1.25nm、平均传输带宽为1.19nm、谐振腔平均品质因数为1350.2、提取的峰值波长调谐范围在1534.04～1653.16nm.结果表明:该滤波器具有正规化传输率高、带宽窄、波长信号提取强度平稳等特性.其结构在密集型波分解复用(DWDDM)系统设计、光信号传感器件设计、密集型光路集成化设计等领域具有潜在的应用价值.

基于石墨烯和1维光子晶体的THz宽带吸收器

为了获得宽带高效率光波吸收器,设计了石墨烯和1维光子晶体的复合结构,采用修正的传输矩阵法研究了其传输特性。结果表明,在一定条件下,复合结构在太赫兹波段具有一定带宽和高效率的吸收带,吸收带的位置和宽度与1维光子晶体通带一致;在一些特别的吸收带,吸收峰值达到1;对相同的结构吸收结果还与入射方向有关。石墨烯和1维光子晶体的结合进一步拓展了它们的应用范围。

消逝波在普通介质1维光子晶体中的传输

为了研究消逝波在常规介质构成的无缺陷的1维光子晶体中的传输特性,采用特征矩阵法进行数值计算。得到在入射角大于全反射临界角时,在很宽的禁带背景中,透射谱存在一系列通带的结果。每个通带由分离的透射峰组成;电磁波是以微腔共振模通过消逝波耦合的方式传播。结果表明,利用消逝波的这种传输特性,可以设计高Q值多通道滤波器。

Complex band structures of 1D anisotropic graphene photonic crystal

The complex band structures of a 1D anisotropic graphene photonic crystal are investigated, and the dispersion relations are confirmed using the transfer matrix method and simulation of commercial software. It is found that the result of using effective medium theory can fit the derived dispersion curves in the low wave vector.Transmission, absorption, and reflection at oblique incident angles are studied for the structure, respectively.Omni-gaps exist for angles as high as 80° for two polarizations. Physical mechanisms of the tunable dispersion and transmission are explained by the permittivity of graphene and the effective permittivity of the multilayerstructure.

Size effect on light propagation modulation near band edges in one-dimensional periodic structures

Periodic photonic structures can provide rich modulation in propagation of light due to well-defined band structures.Especially near band edges,light localization and the effect of near-zero refractive index have attracted wide attention.However,the practically fabricated structures can only have finite size,i.e.,limited numbers of periods,leading to changes of the light propagation modulation compared with infinite structures.Here,we study the size effect on light localization and near-zero refractive-index propagation near band edges in one-dimensional periodic structures.Near edges of the band gap,as the structure's size shrinks,the broadening of the band gap and the weakening of the light localization are discovered.When the size is small,an added layer on the surface will perform large modulation in the group velocity.Near the degenerate point with Dirac-like dispersion,the zero-refractive-index effects like the zero-phase difference and near-unity transmittance retain as the size changes,while absolute group velocity fluctuates when the size shrinks.

Enhanced spectral splitting in a novel solar spectrum optical splitter based on one dimensional photonic crystal heterostructure

Controlling the distribution of solar spectrum in different bands would boost the energy harvesting efficiency and optimize the energy dispatchability.1D photonic crystal with intrinsic optical band gap can be used to split the solar spectrum for hybrid photovoltaic/thermal solar applications.Here,we designed an efficient solar spectrum optical filter based on a cermet layer,Si/SiO_(2)1D photonic crystal,and top heterostructure layer.Compared with 1D photonic crystal structure,the 1D photonic crystal heterostructure with top YSZ layer can realize the reflectance of greater than 92%in PV band and the low average reflectance in two thermal bands by tuning the effective impedance of multilayer films.The enhanced reflectance in PV band results from the huge mismatching of impedance between free space and the heterostructure structure.The top dielectric layer can also be extended to other oxides.

Bending Loss Analysis of Optical Fiber with Out-Cladding of Photonic Crystals

A new type of optical fiber is presented here. It consists of a coaxial optical fiber, bounded by dielectric, multilayer and omnidirectional reflecting mirrors. Jones matrix method is used to analyze the influence of the layer number of one Dimensional (1D) photonic crystals on their reflectivity. The numerical results show that this type of fiber can be used to guide light around sharp bends whose radius of curvature can be as small as the wavelength of light without significant scattering losses.

镉离子响应性凝胶光子晶体传感膜的构建

将光子晶体与响应性水凝胶结合,采用"三明治"填充方法,以聚苯乙烯(PS)胶体晶体为模板,丙烯酰胺和烯丙基硫脲为单体制备得到一种对镉离子具有特异响应性的凝胶光子晶体传感膜,并对其进行了形貌表征和响应性研究。结果表明,该传感膜具有排列整齐的反蛋白石结构,可对不同浓度的Cd2+输出不同的光学信号。随着Cd2+浓度的增大,传感膜的Bragg衍射峰发生蓝移,并伴随有显著的颜色变化。在最优配比,适宜p H和离子强度条件下,衍射峰的最大位移值可达51.1 nm。在研究过程中发现其他干扰金属离子的存在不会影响传感膜对Cd2+的特异性响应,并且表现出了较快的响应速度。在多次循环实验中传感膜由于具备高度交联结构而表现出了良好的机械性和化学稳定性。该传感膜的构建为Cd2+的快速高效及裸眼可视检测提供了可能性。

光子晶体制作反射型相位补偿器的理论研究

为了制作新的光子晶体器件,采用传输矩阵法,通过数值计算,研究了3种一维光子晶体制作的反射型相位补偿器。引入反射振幅系数比的两个参数分别对这3种不同结构组成的补偿器进行讨论。分析结果表明,这些反射型相位补偿器都具有反射率极高、相位补偿连续可调等优点。

TiO_2/SiO_2一维光子晶体的制备及其光子带隙特性

以普通载玻片为基体,采用溶胶-凝胶法制备了 TiO2/ SiO2 一维光子晶体,对该结构的截面形貌、各层厚度及结晶形态、反射谱特性进行了分析。 结果表明：TiO2 和 SiO2 膜的平均厚度分别为 69 nm 和 83 nm,结晶形态分别为锐钛矿和无定形态;该结构在波长 544 nm 处的反射率达到了 94% ,且其 FWHM = 194 nm（486 - 680nm） 。 运用传输矩阵法对该结构进行仿真计算,得到的计算结果与测试结果趋于一致。 最后讨论了入射角对一维光子晶体反射谱的影响。

基于一维缺陷光子晶体的角度测量仪的设计

提出用一维缺陷光子晶体来测量角度特别是小的角度变化的设计方案。用Si薄膜和SiO2薄膜组成一维缺陷光子晶体,用特征矩阵法研究该光子晶体的禁带中的缺陷模的波长和强度随入射角缓慢变化而变化的规律,由此提出根据缺陷模的波长、强度、偏振性与入射角的关系进行角度测量的原理。本设计特别适用于极小的角度变化的测量。

一维缺陷光子晶体多个禁带中的窄带缺陷模

用特征矩阵法研究了一维缺陷光子晶体的透射谱。结果发现:在一维缺陷光子晶体的透射谱中的多个禁带内都有窄带缺陷模,窄带缺陷模的波长越大,其宽度越大;当入射角增大后,波长越长的窄带缺陷模的强度变化越小,位置向短波方向移动越多,且S偏振光与P偏振光的窄带缺陷模的分离越大;增大一维缺陷光子晶体中周期性介质的厚度,窄带缺陷模的波长和移动的范围都增大。本研究对一维缺陷光子晶体的窄带缺陷模的选择使用具有重要意义。