Waves In One-dimensional Photonic Crystals Research Articles

Theoretical investigation of the nonreciprocal bistable absorption of electromagnetic waves in one-dimensional photonic crystals combined with the nonlinear magnetized plasma defect layer

In this paper, we investigate the nonreciprocity bistable absorption of a one-dimensional photonic crystals combined with a novel nonlinear magnetized plasma defect layer. It is figured out that the structure has apparent nonreciprocity, bistable positive and negative absorption of the forward and backward incidences under the nonlinear magneto-optical effect. In addition, the tuning effects of the external magnetic fields and angles are studied. The consequences indicate that the two have significantly opposite working modulation effects on the bistable working range and absorptance. Specifically, the external magnetic field leads to individually controlling the bistability switch-down threshold, and the angle can affect the switch-up and switch-down thresholds concurrently. In the simulation of the electric field diagrams of the proposed structure, the incident side is larger than the transmitted to verify these negative absorption properties. The external magnetic fields and angles will form an alternating conversion between positive and negative absorption with different transmitted intensities. Considering the significance of theoretical experimental verification, concise and feasible experimental schemes are given. This work provides a constructive proposal for the design of magnetization modulated isolators for the nonlinear magnetized plasma materials.

Tunable optical bistability based on Bloch surface waves in one-dimensional photonic crystal with graphene

Graphene possesses large nonlinear conductivity in terahertz region, which makes it a very promising material for nonlinear bistable devices. In this paper, we theoretically study the optical bistability (OB) of reflected beam in a multilayer structure with graphene embedded between the truncated layer and the substrate. The Bloch surface wave excited by the one-dimensional photonic crystal (1D PC) coupling structure significantly enhances the local electric field near the nonlinear graphene, which provides a positive condition for the realization of low-threshold OB. Through parameter optimization, we obtain a threshold electric field with an incident electric field of 105 V/m levels. Furthermore, the influences of graphene’s Fermi energy and relaxation time, as well as those of the incidence angle, on the hysteretic behavior and the threshold of OB are clarified. This approach may provide a feasible scheme for the nonlinear optical bistable devices.

Directional luminescence of the diamond NV center via Bloch surface waves in one-dimensional photonic crystals

In this work, we numerically study the luminescence of nanodiamonds with NV centres embedded in a polymer layer on the surface of one-dimensional photonic crystal. The interaction of NV center spontaneous emission with the Bloch surface wave (BSW) is demonstrated. The presence of a photonic crystal leads to a change in the angular distribution of the emitter radiation due to the coupling of luminescence to BSW. We show that the best coupling efficiency of 71% is observed when NV centres are located in the close proximity to the BSW field maximum.

Plasmonic-Silver Sorets and Dielectric-Nd2O3 nanorods for Ultrasensitive Photonic Crystal-Coupled Emission

Nanocavities forms the basis for plasmon-enhanced luminescence-based sensing technologies. Although surface plasmon-coupled emission platform has progressed with interdisciplinary applications, detrimental Ohmic losses in them hamper luminescence enhancement. An analogous micro-photonic platform, photonic crystal-coupled emission platform overcomes these limitations with Purcell–enhanced luminescence augmentation. Ag soret colloids presenting interfacial nanovoids offered amplified emission enhancements while coupling with Bloch surface waves in one-dimensional photonic crystal. A highly desirable synergistic approach with the use of plasmonic-silver nanoassembly (soret) and dielectric, high refractive index, Nd2O3 ‘Huygen’ sources (efficient forward light scatterers) have been comprehensively studied with added understanding from numerical calculations. A judicious synergy of metal and dielectric plasmonics with photonic crystal interface is demonstrated with new biophysicochemical insights. Fluorescence enhancements, directional and polarized emission obtained in excess of 1200-fold was utilized for attomolar sensing of xenobiotic Rhodamine B dye in integrated cavity ‘hotspots’ due to amplified electromagnetic field intensity.

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.

Spin Hall effect of tunneling mode in one-dimensional photonic crystal based on frustrated total internal reflection

The spin Hall effect of light (SHEL) upon reflection and refraction of p and s waves in one-dimensional photonic crystal (1DPC) tunneling mode based on frustrated total internal reflection (FTIR) is investigated in this paper. We discuss the SHEL in three different cases based on both theoretical derivation and simulation. These results have demonstrated that the SHEL in 1DPC can be enhanced significantly when the designed 1DPC structure simultaneously satisfies both high reflection coefficient of p-wave and high transmission rate of s-wave. A transverse shift of 28.47 μm (equivalent to 45λin length) can be achieved in the structure without any amplification method, which is much larger than those previously reported in literature.

Photonic transmission spectra in graphene-based Gaussian random multilayers

The light-matter interaction is a very active and attractive research field and it is the basis of the photonic devices based on the generation, processing and storage of photons. In this work, we theoretically study the propagation of electromagnetic waves in one-dimensional photonic crystals consisting of two different dielectric slabs (silicon dioxide and titanium dioxide) separated by graphene. The spatial arrangement of the slabs is periodic, but we introduce randomness by using a Gaussian distribution of thickness with a specific standard deviation σ. The well-known transfer-matrix method is used as the mathematical approach. Our main goals are to investigate how the presence of such randomness can change the light transmission spectra and the emergence of robust photonic band gaps. For a given angle of incidence, our numerical results show that the two lowest frequency bandgaps are insensitive to the influence of the Gaussian distribution. Those band gaps emerge from two different mechanisms: one is due to the presence of graphene, while the other is due to the Bragg's scattering. A strong transmission dependence on the standard deviation σ is also observed in our numerical results. More interesting, for the transversal magnetic case (angle of incidence θ=60∘) the system can be adjusted to present transmission coefficient near to 1 and work like a perfect transparent media, what is useful for technological applications.

On the Calculation of the Spectral Bands of One-Dimensional Photonic Crystals

In this work we consider the propagation of transverse electromagnetic waves in one-dimensional photonic crystals consisting of periodic arrays of slabs. On the basis of the Floquet theory we obtain the characteristic function of the periodic medium, which defines the photonic bands of the crystal. The characteristic function is constructed from the monodromy matrices of the slabs. Entries of monodromy matrices are explicitly given as power series of the spectral parameter. The present analysis can be applied not only to homogeneous slabs, but also to slabs with varying refractive indexes. The power series representation of the entries of monodromy matrices leads to an effective numerical method for the calculation of the spectral bands of one-dimensional photonic crystals.

Optical Effects Induced by Bloch Surface Waves in One-Dimensional Photonic Crystals

The review considers the influence of Bloch surface waves on the optical and magneto-optical effects observed in photonic crystals; for example, the Goos–Hanchen effect, the Faraday effect, optical trapping and so on. Prospects for using Bloch surface waves for spatial light modulation, for controlling the polarization of light, for optical trapping and control of micro-objects are discussed.

Thin layer fluorescence microscopy based on one-dimensional photonic crystal

A new method of specimen illumination for wide-field fluorescence microscopy has been presented. This method allows to excite the fluorescence in a thin near-surface layer of the studied object. As a result, the captured images have greater contrast and signal-to-background ratio in comparison with the epifluorescence ones. The long-range surface waves in one-dimensional photonic crystal have been used to localize the electromagnetic field exciting the fluorescence. An experimental setup has been created to excite the surface waves and obtain images of the objects from the near-surface layer. For an illustration of the possibilities of our method, we conducted several experiments with specimens that are typical for fluorescence microscopy, such as bacteria and eukaryotic cells.

Biosensors based on Bloch surface waves in one-dimensional photonic crystal with graphene nanolayers.

In biosensors research, much effort has been made to achieve high sensitivity to detect lower concentrations of analyte in a solution by testing different kinds of materials. In this paper, we present a biosensor based on Bloch surface waves made of photonic crystal (PhC) including graphene nanolayers under the Kretschmann configuration. The band structures, surface modes, reflectivity, and sensitivity of the PhC biosensor are calculated by the transfer matrix method and results are compared with those of the structure without graphene layers. Our investigations show that the angular sensitivity of the biosensor considerably increases in the presence of the graphene layers. Moreover, we study the effect of the number of the graphene layers placed on the surface of the biosensor on the performance of our proposed biosensor. The results reveal that the sensitivity of the biosensor is enhanced by increasing the number of graphene layers on the surface due to the π-stacking interactions between graphene's honeycomb cells and the carbon rings in biomolecules. Furthermore, our results show that the phase sensitivity is higher than the angular sensitivity, which can promote the accuracy of the calculations.

Transverse-magnetic-polarized Floquet–Bloch waves in one-dimensional photonic crystals

Using binary and sinusoidal photonic crystals as examples, it is shown how to construct two independent Floquet–Bloch waves for TM-polarized light in a lossless one-dimensional periodic structure. Particular attention is given to those special situations where either one Bloch wave and a hybrid Floquet mode develop inside the structure (instead of two Bloch waves) or both developed Bloch waves become periodic functions.

Tunable phase compensator based on one-dimensional photonic crystals with single-negative materials

The reflection phase difference between TE and TM waves in one-dimensional photonic crystals composed of single-negative (SNG) (permittivity- or permeability-negative) materials is investigated by transfer matrix method. Within two omni-directional gaps the reflection phase difference changes smoothly and increases with the increasing of the incident angle. In the center of the second omni-directional gap the reflection phase difference remains almost unchanged in a broad frequency band. Especially, at both the edges of the second omni-directional gap the reflection phase difference keeps zero in spite of the change of incident angle. Based on these properties, a continuously tunable phase compensators and an omni-directionally synchronous reflector for TE and TM waves can be designed. The working frequencies for the phase compensators and synchronous reflector are tunable.

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.

Surface wave-induced enhancement of the Goos-Hänchen effect in one-dimensional photonic crystals

The excitation conditions of surface electromagnetic waves in one-dimensional photonic crystals (Bragg reflectors) are studied. Surface electromagnetic waves are visualized by the far-field optical microscopy of the surface of the photonic crystal. The enhancement of the Goos-Hanchen effect by surface electromagnetic waves excited in one-dimensional photonic crystals has been experimentally observed. The Goos-Hanchen shift reaches 30λ for a wavelength of λ = 532 nm.

Bloch oscillations in one-dimensional photonic crystal coupled microcavity composed of single-negative materials

We have studied the propagation properties of electromagnetic waves in one-dimensional photonic crystal coupled microcavity structure composed of single-negative materials. Two Wannier–Stark ladders can be obtained by employing only one type of microcavity. The dynamics behavior of a Gaussian pulse transmitting through the structure is simulated theoretically. We demonstrated for the first time that even in this multilayered structure completely made of single-negative materials, the optical Bloch oscillations and Zener tunneling can also be attained.

Generalized eigenproblem of hybrid matrix for Bloch-Floquet waves in one-dimensional photonic crystals

We present a stable method for analysis of light propagation in one-dimensional photonic crystals that may be composed of general bianisotropic media. Our method is based on the solutions to a generalized eigenproblem of hybrid matrix. It enables Bloch-Floquet waves to be determined reliably and overcomes the numerical instability in the standard eigenproblem of transfer matrix. When the unit cell is lossy and electrically thick, the transfer matrix or its characteristic polynomial may become ill-conditioned, whereas the hybrid matrix is always well-conditioned. Using the imaginary part of Bloch-Floquet wavenumbers, we demonstrate that it is convenient to determine (if any) the frequency range of omnidirectional reflection. Some numerical results are illustrated to investigate the effects of chirality, loss, and tunable anisotropy.

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.

Wave propagation inside one-dimensional photonic crystals with single-negative materials

The propagation of light waves in one-dimensional photonic crystals (1DPCs) composed of alternating layers of two kinds of single-negative materials is investigated theoretically. The phase velocity is negative when the frequency of the light wave is smaller than the certain critical frequency ω cr , while the Poynting vector is always positive. At normal incidence, such 1DPCs may act as equivalent left-handed materials. At the inclined incidence, the effective wave vectors inside such 1DPCs do refract negatively, while the effective energy flows do not refract negatively. Therefore, at the inclined incidence, the 1DPCs are not equivalent to the left-handed materials.

Semiclassical coupled wave theory for TM waves in one-dimensional photonic crystals

Semiclassical coupled wave theory is extended to waves with the electric field polarized parallel to the plane of incidence (TM waves) in one-dimensional periodic dielectric structures. Using this theory, the bandwidths and reflection/transmission characteristics of such structures, as functions of the incident wave frequency, are in good agreement with exact numerical simulations even for very high refractive index contrast.