One-dimensional Photonic Crystal Research Articles

MATLAB simulation based study on poliovirus sensing through one-dimensional photonic crystal with defect

The present work, theoretically examined the poliovirus sensor model composed of one-dimensional photonic crystal with defect. The transfer matrix method with the help of MATLAB software has been used to detect poliovirus present in the water sample. The main objective of the present work is to design an efficient sensor by identifying the minute variation in the refractive index of water sample due to change in the poliovirus concentration present in the sample. The alternate layers of aluminum nitride and gallium nitride has been taken to realize Bragg reflector having defect layer of air at center of the Bragg reflector. The effect of change in thickness of defect layer region, period number and incident angle corresponding to transverse electric wave has been examined to optimize the structure which correspond maximum performance of the proposed poliovirus sensing structure. The maximum performance of the structure has been obtained with optimum value of defect layer thickness 1200 nm, period number 10 and incident angle 40°. Under optimum condition maximum sensitivity of 1189.65517 nm/RIU has been obtained when the structure is loaded with waters sample of poliovirus concentration C = 0.005 g/ml whereas figure of merit, quality factor, signal to noise ratio, dynamic range, limit of detection and resolution values become 2618.28446 per RIU, 3102.06475, 2.27791, 2090.99500, 1.91E−05 and 0.24656 respectively.

Miniaturized Bloch Surface Wave Platform on a Multicore Fiber

We propose a novel implementation of a miniaturized photonic platform fabricated on a multicore fiber tip, capable of tunable optical functions via coupling to Bloch surface waves (BSWs). A one-dimensional photonic crystal is deposited on the cleaved surface of a fiber tip, allowing the propagation of BSWs in the near-infrared. On top of each core, subwavelength gratings are fabricated to operate as optical couplers between BSWs and the corresponding fiber modes. The ability to control the optical interconnection among different pairs of cores of the multicore fiber via polarization-selective BSW coupling is demonstrated. The resulting compact, tunable, and portable platforms can be fruitfully employed in the vast application domain covered by optical fiber technology including sensing, optical trapping, manipulation, and information processing.

Radiation and transition losses in curved waveguides for Bloch surface waves

One-dimensional photonic crystals that support the propagation of Bloch surface electromagnetic waves attract the interest of researchers as an alternative platform for integrated optics with potential applications in nanophotonics, sensing, and optical manipulation of micro- and nanoparticles. In this paper, we numerically study the properties of surface wave modes in curved waveguides on top of a one-dimensional photonic crystal. It is shown that, when the waveguide is bent, an additional channel of radiation losses appears, which is associated with light leakage from the surface wave mode into bulk modes of the photonic crystal, and the waveguide mode profile becomes asymmetric with respect to the middle of the waveguide. We also determine the conditions for minimizing transition losses, which occur at the junctions of waveguides with different curvatures, by transverse displacement of the waveguide facets relative to each other.

Tunable Fano resonance and optical switching in the one-dimensional topological photonic crystal with graphene

A hybrid structure composed of a grating coupled graphene structure and two one-dimensional photonic crystals (PhCs) is investigated, where the topological edge state (TES) and the graphene surface plasmon polariton (GSPP) are coupled to generate Fano resonances. The grating coupled graphene structure is used to excite the GSPP and provides a broad resonance. The two PhCs are designed to possess opposite topological properties; thus, the TES appears at the interface and exhibits a narrow resonance. The constructive and destructive interference between the GSPP and the TES results in the Fano resonance. By analyzing the resonant behaviors, it is found that the line shape of Fano resonance can be actively tuned by the graphene Fermi energy. We apply our results to the optical switching, a high-performance optical switch is achieved, and the modulation depth can reach as high as 23.31 dB. In addition, owing to the characteristic of Fano resonance with steep dispersion and asymmetric profile, our designs might offer an alternative strategy to achieve potential applications in sensors, filters, optical switches, and slow-light devices.

Designing the Structure of a One-Dimensional Photonic Crystal with a Given Spectrum of the Reflection Coefficient

A method for solving the inverse problem of designing the structure of a one-dimensional photonic crystal is proposed and experimentally implemented. It is known that a one-dimensional photonic crystal with a spatial sinusoidal modulation of the refractive index, has a narrow photonic bandgap at a frequency related to the spatial frequency of this sinusoid. A reverse engineering method is proposed for one-dimensional photonic crystals with an arbitrary given reflection spectrum by expanding this spectrum into elementary photonic band gaps and then summing them. The application of this method to fabricate examples of photonic crystals with simple shapes of spectral reflection curves is demonstrated.

Parametric study of 1D plasma photonic crystals with smooth and discontinuous density profiles

Plasma photonic crystals (PPCs) have the potential to significantly expand the capabilities of current millimeter wave technologies by providing high speed (microsecond time scale) control of energy transmission characteristics in the GHz through low THz range. Furthermore, plasma-based devices can be used in higher power applications than their solid-state counterparts without experiencing significant changes in function or incurring damage. Plasmas with periodic variations in density can be created externally, or result naturally from instabilities or self-organization. Due to plasma's diffuse nature, PPCs cannot support rapid changes in density. Despite this fact, most theoretical work in PPCs is based on solid-state photonic crystal methods and assumes constant material properties with abrupt changes at material interfaces. In this work, a linear model is derived for a one-dimensional cold-plasma photonic crystal with an arbitrary density profile. The model is validated against a discontinuous Galerkin method numerical solution of the same device configuration. Bandgap maps are then created from derived group velocity data to elucidate the operating regime of a theoretical PPC device. The bandgap maps are compared for one-dimensional PPCs with both smooth and discontinuous density profiles. This study finds that bandgap behavior is strongly correlated with the density profile Fourier content and that density profile shapes can be engineered to produce specific transmission characteristics.

One-dimensional metamaterial photonic crystals comprising gyroidal and hyperbolic layers as an angle-insensitive reflector for energy applications in IR regions

One-dimensional metamaterial photonic crystals comprising gyroidal and hyperbolic layers as an angle-insensitive reflector for energy applications in IR regions

Total reflectivity for infrared radiation based on one-dimensional gyroidal metallic photonic crystals

In this research, a one-dimensional photonic crystal with such a novel and simple design is introduced to serve as an efficient reflector for infrared (IR) wavelengths. The construction of the proposed photonic crystal design based on the gyroidal geometry is the mainstay of this research to investigate the total reflectivity through a wide band of IR wavelengths. In this regard, [Air/(A/B)10/substrate] is indeed the configuration of the suggested photonic crystal structure. The layer symbols, A and B represent two layers of silver with a gyroidal configuration in host materials of titanium dioxide and silicon, respectively. Meanwhile, our numerical findings demonstrate the existence of a cutoff feature at a wavelength of 1[Formula: see text][Formula: see text]m of the propagating electromagnetic waves. Moreover, the filling fraction of sliver through layers (A) and (B) provides a substantial role in the tunability of the cutoff frequency and the reflectivity of the structure as well. Then, we have taken into account how the host material’s thicknesses and refractive indices will affect the proposed structure’s reflectance. In particular, the refractive index of the host material could lead to a significant variation of the permittivities of the considered materials. Finally, we think that the proposed structure may be of a great interest in a variety of physical and engineering applications including the optical reflectors, smart windows and solar cells applications as well.

Incident-side-dependent mirror based on 1D photonic crystals containing VO2 nanoparticles

The optical properties of an incident-side-dependent mirror based on a one-dimensional photonic crystal composed of nanocomposite layers containing vanadium dioxide nanoparticles were investigated theoretically using the transfer matrix method in the near-infrared spectral range. The influence of the incident angle and filling fraction of the vanadium dioxide nanoparticles on the reflectance and transmittance of the structure were studied. We found that the mirror is an incident-side-dependent reflector with nearly zero transmittance in the photonic bandgap regions. The incident-side-dependent properties of the mirror are more pronounced when the vanadium dioxide nanoparticles are in their metal phase. In addition, the mirror is a perfect reflector for incoming rays from one side and a perfect absorber for incoming rays from the opposite side. Such temperature-controlled and incident-dependent mirrors may find application in the design of various intelligent windows.

A Highly Sensitive and Specific Photonic Crystal-Based Opioid Sensor with Rapid Regeneration.

Opioid misuse and overdose have caused devastating public health challenges and economic burdens, calling for the need of rapid, accurate sensitive opioid sensors. Here, we report a photonic crystal-based opioid sensor in the total internal reflection configuration, providing label-free, rapid, quantitative measurements through change of the refractive index. The one-dimensional photonic crystal with a defect layer that is immobilized with opioid antibodies acts as a resonator with an open microcavity. The highly accessible structure responds to analytes within a minute after the aqueous opioid solution is introduced, achieving the highest sensitivity of 5688.8 nm/refractive index unit (RIU) at the incident angle of 63.03°. Our sensor shows a limit of detection (LOD) of 7 ng/mL for morphine in phosphate-buffered saline (PBS, pH 7.4) solutions, well below the required clinical detection limit, and an LOD of 6 ng/mL for fentanyl in PBS, close to the clinical requirement. The sensor can selectively detect fentanyl from a mixture of morphine and fentanyl and be regenerated in 2 min with up to 93.66% recovery rate after five cycles. The efficacy of our sensor is further validated in artificial interstitial fluid and human urine samples.

Angle-insensitive topological interface states in hybrid one-dimensional photonic crystal heterostructures containing all-dielectric metamaterials.

Topological interface states (TISs) in conventional one-dimensional (1D) photonic crystal (PhC) heterostructures strongly shift toward higher frequencies as the incident angle increases. This strong blueshift property of TISs intensively limits the operating angle ranges of TISs. Herein, we design two angle-insensitive photonic bandgaps (PBGs) in two hybrid 1D PhCs containing all-dielectric metamaterials. By cascading these two hybrid 1D PhCs to construct a hybrid 1D PhC heterostructure, we achieve an angle-insensitive TIS under transverse magnetic polarization. Empowered by the angle-insensitive property of the PBGs, the angular tolerance of the TIS reaches 69.65°, which is much higher than those of the TISs in conventional 1D PhC heterostructures. In addition, the angle-insensitive property of the TIS is robust against the layer thickness. Our work provides a viable route to achieving TISs with high angular tolerances and would facilitate the applications of photonic topological states.

Strongly enhanced light-matter coupling of monolayer WS2 from a bound state in the continuum.

Exciton-polaritons derived from the strong light-matter interaction of an optical bound state in the continuum with an excitonic resonance can inherit an ultralong radiative lifetime and significant nonlinearities, but their realization in two-dimensional semiconductors remains challenging at room temperature. Here we show strong light-matter interaction enhancement and large exciton-polariton nonlinearities at room temperature by coupling monolayer tungsten disulfide excitons to a topologically protected bound state in the continuum moulded by a one-dimensional photonic crystal, and optimizing for the electric-field strength at the monolayer position through Bloch surface wave confinement. By a structured optimization approach, the coupling with the active material is maximized here in a fully open architecture, allowing to achieve a 100 meV photonic bandgap with the bound state in the continuum in a local energy minimum and a Rabi splitting of 70 meV, which results in very high cooperativity. Our architecture paves the way to a class of polariton devices based on topologically protected and highly interacting bound states in the continuum.

Dual-responsive photonic multilayers in combination with a smartphone application as high-security anti-counterfeiting devices

A new concept for dual-responsive one-dimensional (1D) photonic crystal (PC) multilayers is proposed herein. The novel PC-based systems rely on the humidity from the human breath and fluorescence triggered by Al3+ coordination to act as high-security anti-counterfeiting labels to be used in combination with a smartphone application. The dual-responsive patterned film is fabricated via the alternating deposition of photo-crosslinkable poly(2-vinylnaphthalene-co-benzophenone acrylate) and 51%-quaternized poly(4-vinylpyridine-co-benzophenone acrylate) onto a transparent polyethylene terephthalate substrate to obtain 1D PC multilayers, followed by the introduction of a poly([(2-hydroxybenzylidene)-4-vinylbenzohydrazide-co-benzophenonyl acrylate) top coating. The obtained system is then exposed to ultraviolet light irradiation through variously patterned masks. The patterned films exhibit vivid dual color transitions in high-humidity environments along with remarkable turn-on fluorescence, following the coordination of Al3+ ions upon spraying with a 1 wt% Al(NO3)3 solution. Notably, the efficacy of the combination between the two-step security function of the flexible patterned multilayer films and a smartphone app was also demonstrated. The first level of security involves the determination of the RGB color value before and after a color change triggered by blowing onto the film. The second level of security involves the revelation of hidden fluorescent shapes under ultraviolet light irradiation after Al(NO3)3 spraying.

Butyl acrylate/TiO2–copolymer hybrid one-dimensional photonic crystal–based colorimetric sensor for detection of C6–C16 n-alkanes of kerosene in adulterated diesel

Diesel fuel, which is widely used in engines, generators, and industrial equipment, is often adulterated with kerosene. The use of adulterated diesel fuel reduces the performance and durability of diesel–fuel-powered engines, causes environmental pollution, and promotes tax evasion. However, detecting kerosene in diesel using a high-precision instrumental technique such as gas chromatography with flame ionization detection is difficult because both diesel and kerosene contain C6–C16 paraffins. In this study, we developed a simple and reliable colorimetric sensor to detect various volumetric fractions of kerosene in diesel. A novel 15-layered one-dimensional photonic crystal (1D PC) was prepared using a photo-crosslinked butyl acrylate (BA)–based copolymer [P(BA-co-BPA)] as the low-refractive-index material and a photo-crosslinked copolymer–TiO2 hybrid (Ti70) as the high-refractive-index material. The P(BA-co-BPA) layers swelled to a greater extent in smaller-sized C6–C16n-alkanes than in the larger ones. Consequently, the reflection colors of P(BA-co-BPA)/Ti70 PC underwent a greater red shift from the sky-blue color of the pristine state as the swelling increased from the C16 to the C6n-alkanes. When immersed in pure diesel, the 1D PC exhibited a green color, which underwent a greater red shift as the volume fraction of kerosene increased from 10% (∼limit of colorimetric detection) to 100% in the kerosene + diesel mixtures. The 1D PC reached saturation within 45 min and changed color from the sky-blue corresponding to the pristine state to greenish yellow, yellow, yellow-orange, orange, and reddish orange in 10%, 20%, 30%, 50–70%, and 100% kerosene, respectively. Moreover, it exhibited recyclability in five swelling/deswelling cycles in diesel and kerosene. We expect that these findings will promote the development of simple and state-of-the-art 1D PC sensors.

Design and analysis of optical biosensor based on symmetric and asymmetric structured one-dimensional photonic crystal for tuberculosis detection

We looked into three distinct topologies, using a one-dimensional photonic crystal with a defect layer in two symmetrical and one asymmetrical configurations as an optical biosensor application for detection in tuberculosis (TB). In order to investigate the optical transmission characteristics of such structures, we used a well-known transfer matrix approach. A shift in resonant peak is estimated, when blood of healthy or TB infected human is infiltrated in defect layer. The impact of several parameters, including the thickness of the defect layer, the number of unit cells, and the angle of incidence for all three configurations, has been studied. The sensitivity, quality factor, figure of merit, and detection limit for all structures have been studied and it is found that asymmetric structure is the best suitable structure for optical sensor application in the present case.

Metamaterials for light extraction and shaping of micro-scale light-emitting diodes: from the perspective of one-dimensional and two-dimensional photonic crystals.

Metamaterials have attracted broad attention owing to their unique versatile micro- and nano-structures. As a kind of typical metamaterial, photonic crystals (PhCs) are capable of controlling light propagation and constraining spatial light distribution from the chip level. However, introducing metamaterial into micro-scale light-emitting diodes (µLED) still exists many unknowns to explore. This paper, from the perspective of one-dimensional and two-dimensional PhCs, studies the influence of metamaterials on the light extraction and shaping of µLEDs. The µLEDs with six different kinds of PhCs and the sidewall treatment are analyzed based on finite difference time domain (FDTD) method, in which the optimal match between the PhCs type and the sidewall profile is recommended respectively. The simulation results show that the light extraction efficiency (LEE) of the µLEDs with 1D PhCs increases to 85.3% after optimizing the PhCs, and is further improved to reach 99.8% by the sidewall treatment, which is the highest design record so far. It is also found that the 2D air ring PhCs, as a kind of left-handed metamaterials, can highly concentrate the light distribution into 30° with the LEE of 65.4%, without help of any light shaping device. The surprising light extraction and shaping capability of metamaterials provides a new direction and strategy for the future design and application of µLED devices.

The transport of dipole solitons in a one-dimensional nonlinear photonic crystal

Quadratic χ(2) nonlinearity crystal provide an ideal stage for the researches of the transport of optical solitons. However, the transport of dipole solitons in a homogeneous χ(2) nonlinear medium is unstable. To solve this problem, a one dimensional nonlinearity photonic crystal is designed from a χ(2) nonlinearity crystal by quasi-phase matching technique. The duty cycle of the positive polarized in the transverse direction of the crystal is periodic modulated, so as to realize a stable transport of dipole solitons in it. Besides, relations of the transportation characteristics of the dipole soliton and the modulation parameters are researched in this letter numerically. Moreover, mobility and collision of these dipole soliton through the crystals are discussed through the paper. Some key parameters of the related experiment are also estimated.

Thermally switchable terahertz absorber based on a VO2-included one-dimensional photonic crystal

Thermally switchable terahertz absorber based on a VO2-included one-dimensional photonic crystal

Switching of lasing direction in reconfigurable chiral photonic crystals

In recent years, the development of lasers using photonic crystals as resonant cavities has emerged and continued to grow. These photonic crystal lasers offer the advantages of reduced threshold levels and compact dimensions. Chiral liquid crystals (CLCs) are self-assembled one-dimensional photonic crystals that enable a wide range of photonic crystal lasers to exhibit broad wavelength tuning capabilities. Our research exploits the uniform standing helix (USH) and uniform lying helix (ULH) states of CLCs as resonant cavities; therefore, the direction of laser emission of CLC lasers can be changed by switching between USH and ULH states. Both USH and ULH lasers in CLCs also exhibit wavelength tuning. The USH laser induces a blue shift in the laser wavelength by dielectric heating, while the ULH laser achieves a redshift of the laser wavelength by applying a vertical electric field to lengthen the helical pitch. Such a reconfigurable chiral photonic crystal laser based on the CLCs provides bidirectional switching of the laser direction while maintaining the ability to tune the wavelength, so it has the potential for use in photonic applications.

Strong nonreciprocal thermal radiation based on topological edge state in one-dimensional photonic crystal with Weyl semimetal

Kirchhoff's law is the theoretical basis for characterizing thermal radiation. The construction of nonreciprocal thermal radiation needs to violate Kirchhoff's law, in which its existing methods usually utilize the magneto-optical effect with an external magnetic field. However, natural materials' relatively weak magneto-optical response in the thermal wavelength range requires a strong or moderate magnetic field. Fortunately, the unique topologically nontrivial electronic state and inherent time-reversal symmetry breaking of Weyl semimetals can exhibit highly unusual and extremely large gyrotropic optical responses in the mid-infrared band without an external magnetic field, which provides a new way to violate Kirchhoff's law. This work theoretically investigates the nonreciprocity of a multilayer structure in which a Weyl semimetal is embedded in two one-dimensional photonic crystals. The results show that the absorptivity and emissivity of the structure almost completely violate Kirchhoff's law over a broad range of angles (7° ∼ 51°) and frequencies (56.4 THz ∼ 65.3 THz) without any external magnetic field. We also discuss the effects of the incident angle, the axial vector of the Weyl semimetal, and the thickness of the Weyl semimetal on the characteristics of nonreciprocal thermal radiation. Furthermore, the electric field distribution reveals that the structurally excited topological edge states significantly enhance the local electric field in the vicinity of the Weyl semimetal, providing positive conditions for the realization of perfect strong nonreciprocal thermal radiation. We hope this work may contribute to the design of strong nonreciprocal thermal emitters.