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Influence of dielectrics with light absorption on the photonic bandgap of porous alumina photonic crystals

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Nano Research 2016年第3期9卷 703-712页

作者： Guoliang Shang Guangtao Fei Yue Li Lide Zhang Key Laboratory of Materials Physics and Anhui Key Laboratory of Nanomaterials and Nanostructures Institute of Solid State PhysicsHefei Institutes of Physical Science Chinese Academy of Sciences P. O. Box 1129 Hefei 230031 China

In this work, the influences of dielectrics with light absorption on the photonic bandgaps （PBGs） of porous alumina photonic crystals （PCs） were studied. Transmittance spectra of porous alumina PCs adsorbing ethanol showed that all the PBGs positions red-shifted; however, the transmittance of the PBG bottom showed different trends when the PBGs were located in different wavelength regions. In the near infrared region, liquid ethanol has strong light absorption, and, with the increase in adsorption, the PBG bottom transmittance of porous alumina PCs first increased and then decreased. However, in the visible light region, liquid ethanol has little light absorption, and thus, with the increase in adsorption, the PBG bottom transmittance of porous alumina PCs increased gradually all the time. Simulated results were consistent with the experimental results. The capillary condensation of organic vapors in the pores of porous alumina accounted for the change in the PBG bottom transmittance. The non- negligible light absorption of the organic vapors was the cause of the decrease in the transmittance. The results for porous alumina PC adsorbing methanol, acetone, and toluene further confirmed the influences of light absorption on the PBG bottomed transmittance.

关键词： photonic crystals porous materials light-mater interaction capillary condensation nanotechnology

Band rules for the frequency spectra of three kinds of aperiodic photonic crystals with negative refractive index materials

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Chinese Physics B 2009年第12期18卷 5313-5325页

作者：全小林杨湘波 MOE Key Laboratory of Laser Life Science & Institute of Laser Life Science South China Normal University

By means of the theory of electromagnetic wave propagation and transfer matrix method, this paper investigates the band rules for the frequency spectra of three kinds of one-dimensional （1D） aperiodic photonic crystals （PCs）, generalized Fibonacci GF（p, 1）, GF（1,2）, and Thue Morse （TM） PCs, with negative refractive index （NRI） materials. It is found that all of these PCs can open a broad zero-n gap, TM PC possesses the largest zero-n gap, and with the increase of p, the width of the zero-n gap for GF（p, 1） PC becomes smaller. This characteristic is caused by the symmetry of the system and the open position of the zero-n gap. It is found that for GF（p, 1） PCs, the possible limit zero-n gaps open at lower frequencies with the increase of p, but for GF（1,2） and TM PCs, their limit zero-n gaps open at the same frequency. Additionally, for the tbree bottom-bands, we find the interesting perfect self-similarities of the evolution structures with the increase of generation, and obtain the corresponding subband-number formulae. Based on 11 types of evolving manners Qi （i = 1, 2,... , 11） one can plot out the detailed evolution structures of the three kinds of aperiodic PCs for any generation.

关键词： negative refractive index photonic crystals generalized Fibonacci photonic crystal Thue-Morse photonic crystal

Realization of energy-saving glass using photonic crystals

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Frontiers in Energy 2018年第1期12卷 178-184页

作者： Yen-Hsiang CHEN Li-Hung LIAO Yu-Bin CHEN Department of Mechanical Engineering Cheng Kung University Tainan701 Taiwan China Department of Power Mechanical Engineering TsingHua UniversityHsinchu 300 Taiwan China

This work successfully developed an energy- saving glass with wavelength selectivity. The glass is composed of a SiO2 substrate and two layers of three- dimensional photonic crystals. Each crystal is composed of identical and transparent polystyrene spheres after their self-assembling. The glass then possesses dual photonic band gaps in the near-infrared region to suppress penetration of thermal radiation. Experimental results show that the energy-saving glass decreases temperature increment in a mini-house. Moreover, the temperature after thermal equilibrium is lower than that inside a counterpart using ordinary glass.

关键词： energy-saving glass photonic crystals poly-styrene spheres self-assembly

Thermal tunable one-dimensional photonic crystals containing phase change material

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Chinese Physics B 2020年第10期29卷 294-299页

作者： Yuanlin Jia Peiwen Ren Chunzhen Fan School of Physics and Microstructures Zhengzhou UniversityZhengzhou 450001China

To obtain the adjustable photonic crystals (PCs), we numerically investigate one-dimensional (1D) PCs with alternating VO2 and SiO2 layers through transfer matrix method. The dispersion relation agrees well with the transmittance obtained by the finite element calculation. Tunable band gaps are achieved with the thermal stimuli of VO2, which has two crystal structures. The monoclinic crystal structure VO2 (R) at low temperature exhibits insulating property, and the high temperature square rutile structure VO2 (M) presents metal state. Concretely, the bandwidth is getting narrower and red shift occurs with the higher temperature in VO2 (R)/SiO2 PCs structure. Based on the phase change characteristics of VO2, we can flexibly adjust the original structure as VO2 (R)/VO2 (M)/SiO2. By increasing the phase ratio of VO2 (R) to VO2 (M), the band gap width gradually becomes wider and blue shift occurs. The discrete layers of gradient composites on the dispersion of 1D PCs are also investigated, which enhances the feasibility in practical operation. Thus, our proposed thermal modulation PCs structure paves a new way to realize thermal tunable optical filters and sensors.

关键词： photonic crystals VO2 thermal modulation phase change

Phase control of spontaneous emission from a double-band photonic crystals

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Chinese Physics B 2010年第5期19卷 306-312页

作者：张珂祝艳萍姜丽张汉壮 College of Physics Jilin University Laboratory of Optical Physics Institute of PhysicsChinese Academy of Sciences

Through the picture of dressed states, this paper investigates the spontaneous emission spectrum from a microwavedriven three-level atom embedded in double-band photonic crystals. The physical dynamics of the phase dependent phenomenon are analysed by comparing two models ＇upper level coupling＇ and ＇lower level coupling＇. When the phase is changed from 0 to π, the variety of spontaneous emission spectra from either of the two models are inverse to each other, in which the relative height and width of the peaks are determined by the density of states in photonic crystals.

关键词： photonic crystals spontaneous emission phase

The photonic Band Gaps in the Two-Dimensional Plasma photonic crystals with Rhombus Lattice

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Plasma Science and Technology 2016年第6期18卷 583-589页

作者：张开明孙东升 School of Physics and Electronics Yancheng Teachers University

In this paper,under two different electromagnetic modes,the photonic band gaps（PBGs） in the two-dimensional plasma photonic crystals（PPCs） are theoretically investigated based on the plane wave expansion *** proposed PPCs are arranged in rhombus lattices,in which the homogeneous unmagnetized plasma rods are immersed in the isotropic dielectric *** computed results showed that PBGs can be easily tuned by the angle of rhombus lattices,and a cutoff frequency and a flatbands region can be observed under the TM and TE polarized waves,*** relationships between the relative bandwidths of first PBGs and the parameters of PPCs in two such cases also are *** numerical simulations showed that the PBGs can be manipulated obviously by the parameters as mentioned *** proposed results can be used to design the waveguide and filter based on the PPCs.

关键词： plasma photonic crystals plane wave expansion method cutoff frequency flatbands region

Relationship between group velocity and symmetry of photonic crystals

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Chinese Physics B 2010年第5期19卷 363-368页

作者：叶卫民罗章袁晓东曾淳 College of Optoelectronic Science and Engineering National University of Defense Technology

Group velocity （GV） of eigenmode is a crucial parameter to explain the extraordinary phenomena about light propagation in photonic crystals （PhCs）. To study relationships between group velocity and symmetry of PhCs, a new general expression of CV in PhCs made up of non-dispersive material is introduced. Based on this, the CVs of eigenmodes of PhCs, especially those of degenerate eigenmodes at highly symmetric points in the first Brillouin zone, are discussed. Some interesting results are obtained. For example, the summation of degenerate eigenmodes＇ CVs is invariant under the operations of wave vector K-group MK. In addition, some numerical results are presented to verify them.

关键词： group velocity symmetry photonic crystals degenerate eigenmode

Transmission spectra characteristics of 1D photonic crystals with complex dielectric constant

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Rare Metals 2011年第2期30卷 150-154页

作者： GAO Yingjun CHEN Haibo QIU Hongguang LU Qianghua HUANG Changgao College of Physical Science and Engineering Guangxi University Nanning 5300041 China Center oflnternational Materials and Physics Chinese Academy of Science Shenyang 110016 China

The characteristics of photonic forbidden bands, transmission gain and absorption of one-dimensional （ID） dual-periodical photonic crystals （PC） with a complex dielectric layer were studied by using the optical transfer matrix （TM） method. The results show that the photonic band gap （PBG） of this structure is enlarged and many transmission resonance peaks appear in PBG. Large transmission gain for transmission peaks is obtained if the imaginary part of dielectric constant is negative. With the increase of the absolute value of the imaginary part, the transmission gain increases firstly and the transmittance gain gets to an apex. The imaginary parts of dielectric constant corresponding to transmission gain apex are different according to wavelength. However, the transmission ratio of resonance peaks is less than 1 if the imagi- nary part of dielectric constant is positive. The properties might be used to design multi-narrow-channel band filters and optical amplification devices synchronously.

关键词： photonic crystals one dimensional dielectric properties dielectric constant photonic band gap

Polarization-independent self-collimating bends and beam splitters in photonic crystals

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Chinese Optics Letters 2007年第11期5卷 662-664页

作者：沈晓鹏韩奎杨先清沈义峰李海鹏唐刚郭治天 Department of Physics School of Sciences China University of Mining and TechnologyXuzhou 221008

Polarization independent bends and beam splitters for transverse electric （TE） and transverse magnetic （TM） polarizations have been demonstrated in two-dimensional （2D） photonic crystals （PhCs）. In virtuel of equi-frequency contour analysis and finite-difference time-domain calculations, self-collimation behaviors for TE- and TM-polarizations are achieved at the same frequency. Simulation results show a 90-degree bend with 90% efficiency and beam splitters with about 96% total efficiency for both TE- and TM- polarizations, where the light is self-guided by the self-collimation effect. Such bends and beam splitters are expected to play important roles in optical devices where polarization insensitivity is needed.

关键词： Calculations Finite difference time domain method photonic crystals Two dimensional