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In this study, we demonstrate the reflectance spectrum of one-dimensional photonic crystals comprising two different types of metamaterials. In this regard, the designed structure can act as a simple and efficient detector for fat concentrations in milk samples. Here, the hyperbolic and gyroidal metamaterials represent the two types of metamaterials that are stacked together to construct the candidate structure; meanwhile, the designed 1D PCs can be simply configured as [G(ED)m]S. Here, G refers to the gyroidal metamaterial layers in which Ag is designed in a gyroidal configuration form inside a hosting medium of TiO2. In contrast, (ED) defines a single unit cell of the hyperbolic metamaterials in which two layers of porous SiC (E) and Ag (D) are combined together. It is worth noting that our theoretical and simulation methodology is essentially based on the effective medium theory, characteristic matrix method, Drude model, Bruggeman's approximation, and Sellmeier formula. Accordingly, the numerical findings demonstrate the emergence of three resonant peaks at a specified wavelength between 0.8 μm and 3.5 μm. In this context, the first peak located at 1.025 μm represents the optimal one regarding the detection of fat concentrations in milk samples due to its low reflectivity and narrow full bandwidth. Accordingly, the candidate detector could provide a relatively high sensitivity of 3864 nm/RIU based on the optimal values of the different parameters. Finally, we believe that the proposed sensor may be more efficient compared to other counterparts in monitoring different concentrations of liquid, similar to fats in milk. [ABSTRACT FROM AUTHOR]

This paper seeks to progress the field of topological photonic crystals (TPC) as a promising tool in face of construction flaws. In particular, the structure can be used as a novel temperature sensor. In this regard, the considered TPC structure comprising two different PC designs named PC1 and PC2. PC1 is designed from a stack of multilayers containing Silicon (Si) and Silicon dioxide (SiO2), while layers of SiO2 and composite layer named hyperbolic metamaterial (HMM) are considered in designing PC2. The HMM layer is engineered using subwavelength layers of Si and Bismuth Germinate, or BGO ( Bi 4 Ge 3 O 12 ). The mainstay of our suggested temperature sensor is mainly based on the emergence of some resonant modes inside the transmittance spectrum that provide the stability in the presence of the geometrical changes. Meanwhile, our theoretical framework has been introduced in the vicinity of transfer matrix method (TMM), effective medium theory (EMT) and the thermo-optic characteristics of the considered materials. The numerical findings have extensively introduced the role of some topological parameters such as layers' thicknesses, filling ratio through HMM layers and the periodicity of HMM on the stability or the topological features of the introduced sensor. Meanwhile, the numerical results reveal that the considered design provides some topological edge states (TESs) of a promising robustness and stability against certain disturbances or geometrical changes in the constituent materials. In addition, our sensing tool offers a relatively high sensitivity of 0.27 nm/°C. [ABSTRACT FROM AUTHOR]

In this study, the transfer matrix method is used to analyze the optical properties of a layered structure, {Air(SrTiO3/BSCCO)20Substrate}, consisting of air, SrTiO3, BSCCO (bismuth strontium calcium copper oxide) bilayers, and a substrate. This paper aims to investigate the transmittance spectra of two proposed one-dimensional (1D) structures, including a conventional superconductor photonic crystal (PC) and a gyroidal superconductor PC at infrared (IR) wavelengths. A comprehensive analysis has been carried out to provide useful insights into the optical properties and the behavior of the proposed structure, highlighting the impact of many parameters, such as refractive index, filling fraction, and layer thickness. The numerical findings showed that the permittivity of the BSCCO superconductor of a gyroidal geometry takes a different response compared to the conventional one. Notably, the filling fraction and refractive index of the host material have a significant control on both real and imaginary parts of the gyroidal BSCCO permittivity through the considered wavelengths. Thus, the proposed design provides high transmittivity outside the obtained photonic band gap compared to the conventional one. We believe that the designed one-dimensional gyroidal BSCCO photonic crystals could act as an efficient reflector through near IR for optoelectronics and energy applications. [ABSTRACT FROM AUTHOR]

Detecting of the levels of greenhouse gases in the air with high precision and low cost is a very urgent demand for environmental protection. Phononic crystals (PnCs) represent a novel sensor technology, particularly for high-performance sensing applications. This study has been conducted by using two PnC designs (periodic and quasi-periodic) to detect the CO2 pollution in the surrounding air through a wide range of concentrations (0–100%) and temperatures (0–180 °C). The detection process is physically dependent on the displacement of Fano resonance modes. The performance of the sensor is demonstrated for the periodic and Fibonacci quasi-periodic (S3 and S4 sequences) structures. In this regard, the numerical findings revealed that the periodic PnC provides a better performance than the quasi-periodic one with a sensitivity of 31.5 MHz, the quality factor (Q), along with a figure of merit (FOM) of 280 and 95, respectively. In addition, the temperature effects on the Fano resonance mode position were examined. The results showed a pronounced temperature sensitivity with a value of 13.4 MHz/°C through a temperature range of 0–60 °C. The transfer matrix approach has been utilized for modeling the acoustic wave propagation through each PnC design. Accordingly, the proposed sensor has the potential to be implemented in many industrial and biomedical applications as it can be used as a monitor for other greenhouse gases. [ABSTRACT FROM AUTHOR]

This study aims to theoretically address the design and analysis of an efficient pressure sensor designed using a polymer-based defective 1D annular photonic crystal (APC). The 1D APC comprises an alternate arrangement of Si and SiO2 in a cylindrical fashion, incorporating a central defect layer. The investigation of the reflectance characteristics of the proposed structure is conducted by separately considering the polystyrene (PS) and the polymethyl methacrylate (PMMA) polymer materials as the defect layer. The pressure-sensitive refractive index of the polymers and the constituent materials of the APC play a vital role in envisaging the pressure-sensing application. The cornerstone of this study is represented by the shift analysis regarding the wavelength of the defect mode inside the band gap using different applied pressures, employing the modified transfer matrix method (MTMM). Various geometrical parameters like the defect polymer layer's thickness and the APC period were carefully optimized to achieve an improved sensing performance. The proposed design demonstrated a remarkable pressure sensitivity and FoM of 51.29 nm/GPa and 301.7 GPa−1, respectively, which is considerably high in the current research scenario. It is believed that the proposed structure can be an apt candidate for an innovative high-performance pressure sensor, and could play a key role in photonic integrated circuits. [ABSTRACT FROM AUTHOR]

This research presented a comprehensive study of a one-dimensional (1D) porous silicon phononic crystal design as a novel fluidic sensor. The proposed sensor is designed to detect sulfuric acid (H2SO4) within a narrow concentration range of 0–15%. Sulfuric acid is a mineral acid extensively utilized in various physical, chemical, and industrial applications. Undoubtedly, its concentration, particularly at lower levels, plays a pivotal role in these applications. Hence, there is an urgent demand for a highly accurate and sensitive tool to monitor even the slightest changes in its concentration, which is crucial for researchers. Herein, we presented a novel study on the optimization of the phononic crystal (PnC) sensor. The optimization process involves a comparative strategy between binary and ternary PnCs, utilizing a multilayer stack comprising 1D porous silicon (PSi) layers. Additionally, a second comparison is conducted between conventional Bragg and local resonant PnCs to demonstrate the design with the highest sensitivity. Moreover, we determine the optimum values for the materials' thickness and number of periods. The results revealed that the ternary local resonant PnC design with the configuration of {silicone rubber/[PSi1/PSi2/PSi3]N/silicone rubber} is the optimal sensor design. The sensor provided a super sensitivity of 2.30 × 107 Hz for a concentration change of just 2%. This exceptional sensitivity is attributed to the presence of local resonant modes within the band gap of PnCs. The temperature effects on the local resonant modes and sensor performance have also been considered. Furthermore, additional sensor performance parameters such as quality factor, figure of merit, detection limit, and damping rate have been calculated to demonstrate the effectiveness of the proposed liquid sensor. The transfer matrix method was utilized to compute the transmission spectra of the PnC, and Hashin's expression was employed to manipulate the porous silicon media filled with sulfuric acid at various concentrations. Lastly, the proposed sensor can serve as an efficient tool for detecting acidic rain, contaminating freshwater, and assessing food and liquid quality, as well as monitoring other pharmaceutical products. [ABSTRACT FROM AUTHOR]

The light-slowing effect near band endpoints is frequently exploited in photonic crystals to enhance the optical transmittance. In a one-dimensional binary photonic crystal (1DPC) made of hyperbolic metamaterials (HMMs), we theoretically examined the angle-dependent omnidirectional photonic bandgap (PBG) for TM polarization. Using the transfer matrix approach, the optical characteristics of the 1DPC structure having dielectric and HMM layers were examined at the infrared range (IR). As such, we observed the existing of numerous PBGs in this operating wavelength range (IR). Meanwhile, the HMM layer is engineered by the subwavelength dielectric- nanocomposite multilayers. The filling fraction of nanoparticles have been explored to show how they affect the effective permittivity of the HMM layer. Furthermore, the transmittance properties of the suggested structure are investigated at various incident angles for transverse magnetic (TM) and transverse electric polarizations. Other parameters such as, the permittivity of the host material, the filling fraction of nanoparticles, and the thickness of the second layer (HMM) are also taken into account. Finally, we investigated the effect of these parameters on the number and the width of the (PBGs). With the optimum values of the optical parameters of the nanocomposite (NC) layer, this research could open the way for better multi-channel filter photonic crystals. [ABSTRACT FROM AUTHOR]

In the current work, we demonstrate a design to act as a Gamma-ray radiation dosimeter based on the one-dimensional photonic crystal (1D-PhC). The basic concept of the present dosimeter is based on a Porous Silicon (PSi) infiltrated by poly-vinyl alcohol (PVA)-polymer doped with crystal violet (CV) and carbol-fuchsine (CF) dyes. The mechanism of suggested dosimeter is based on the shift of the photonic bandgap (PBG) to higher wavelengths as exposed to gamma-ray radiation doses from 0 to 70 Gray (Gy). The basic axes of the current theoretical treatment are the transfers matrix method (TMM), Bruggeman's effective medium equation, and the fitted experimental data to the refractive index of the doped PVA-Polymer. The obtained results showed the proposed sensor is characterized by high stable sensitivity varied from (178–186 nm/ RIU) along an applied γ-dose from (10–70 Gy) in the visible range. In addition, we compared these results with previous researches. In addition, based on the our knowledge may be it is the first time that a 1D-PhC has been used for gamma-ray detection by using (PVA/CV + CF) based on Porous Silicon. [ABSTRACT FROM AUTHOR]

We have theoretically demonstrated and explored the transmittance characteristics of a one-dimensional binary photonic crystal composed of metamaterial (MM) and nanocomposite (NC) layers. The NC layer was designed from silver nanoparticles (Ag-NPs) in a host material as Yttrium oxide (Y2O3). Using the transfer matrix approach (TMM), the optical properties of a one-dimensional binary periodic structure having MM and NC layers in the Giga Hertz (GHz) range were examined. The filling fractions of nanoparticles have been explored to see their effect on the effective permittivity of NC materials. Furthermore, the transmittance properties of the suggested structure were investigated at various incident angles for the transverse electric (TE) polarization. In addition to that, different parameters, such as the thickness of the MM layer, the permittivity of the host dielectric material, the filling fraction, and the thickness of the NC layer are also taken into account. We also discussed the effect of these parameters on the width of the photonic bandgap (PBG). With the optimum values of the optical parameters of NC layer, this research could open the way for better photonic crystal circuits, splitters, switches and others. [ABSTRACT FROM AUTHOR]

In this study, the reflection properties of a one-dimensional dielectric photonic crystal covered with metallic (Ag), and nanocomposite layers were investigated theoretically in visible and near-infrared ranges. The reflection spectra for the normal incident electromagnetic waves were calculated using the transfer matrix method. The optical properties and the effective permittivity of the nanocomposite layer were computed based on the Maxwell–Garnett model. The main target of this research is focused on how the intensity and number of the resonant Tamm plasmon modes can be significantly controlled based on the characteristics of the nanocomposite material. Herein, the numerical results clarify the localization of Tamm plasmon resonance states through the reflectance spectrum of our designed structure. In addition, such resonance is significantly improved by attaching a nanocomposite layer between the Ag layer and PC structure. The effects of the radius of the Ag nanoparticles, the thickness of the nanocomposite layer, and the refractive index of the host dielectric material on the reflection spectra of the proposed structure were discussed. Besides, increasing the radius of Ag nanoparticles through the nanocomposite layer leads to an enhancement in the absorption values of the incident light. Finally, we think the proposed structure could be useful in many optical devices, such as optical switches, sensors, back mirrors for solar cells, and multichannel filters. [ABSTRACT FROM AUTHOR]

We introduce in this research a simple, accurate, safe, and efficient design for the detection of ethyl butanoate that be present in the dry exhaled breath. In particular, the presence of ethyl butanoate in the dry exhaled breath could be utilized as a platform for the diagnosing of COVID 19. The main idea of this theoretical investigation is based on the inclusion of a cavity layer between a thin layer of Au and the well-known one-dimension photonic crystals. Accordingly, the cavity layer is filled with dry exhaled breath. The numerical results are investigated in the vicinity of the Drude model and transfer matrix method. The investigated results show the appearance of Tamm plasmon resonance in the reflectance spectrum of our design through the IR region. Such resonant mode provides very high sensitivity with the change in the concentration of ethyl butanoate. We have examined the performance of the proposed sensor by calculating its sensitivity, detection limit, detection accuracy, quality factor and figure of merit. The designed sensor could receive sensitivity of 0.3 nm/ppm or 260,486 nm/RIU, resolution of 7 ppm and quality factor of 969. [ABSTRACT FROM AUTHOR]

In this work, we have introduced theoretically a novel design of a 1D phononic crystal model acting as a sensor for gasoline components (blends). The proposed sensor is prepared to distinguish between different components of gasoline with high performance. The sensor is designed from a defect layer filled with one of the gasoline blends in the middle of a 1D multilayer phononic crystal configured as, [(lead / epoxy)2 gasoline [(lead / epoxy)2]. The numerical investigations are obtained based on the transfer matrix method and the acoustic properties of the constituent materials. The numerical results showed that our sensing tool can distinguish between different gasoline blends with high selectivity and sensitivity at the same time. In addition, the monitoring of these blends could be obtained. The proposed sensor provides high sensitivity and quality factor that can reach 2.97 × 107 Hz and 5034, respectively. [ABSTRACT FROM AUTHOR]

In this paper, we have introduced a multilayer periodic structure with a defect layer as a sensor for a variety of organic compounds. Here, we have considered the interaction of both electromagnetic and acoustic radiations with the designed sensor, which could offer flexibility in the detection process. Si and MgO are the basic materials in the design of the proposed sensor. In this context, this sensor is configured as {Si (Si/MgO)N (liquid) (MgO/Si)N Si}. The optimization procedure is based on the change of the thickness of the defect layer and the structure's periodicity. The simulation results were carried through the transfer matrix method to calculate the photonic and phononic transmittance. The structure is analyzed of the photonic and acoustic transmittance as the defect layer is filled with water, benzene, DIPE, n‑Heptane, n‑Hexane, and n‑Octane. The analysis includes determining their defect peak frequency, full width at half maximum, quality factor, sensitivity, and figure of merit. The calculated photonic sensitivity for n‑Heptane is 43.8 (THz / RIU) with 154.8 RIU - 1 figure of merit, while its acoustic sensitivity equivalent 1.614 (MHz / ms - 1) with a figure of merit equals 1.06 m / s - 1 . From the simulation results, the structure shows a promise response for sensing different organic compounds with high sensitivity. [ABSTRACT FROM AUTHOR]

In the present work, we introduce a study about the reflectance properties of a one-dimensional superconductor photonic crystal in a different manner. Our structure is designed from alternately layers of high-temperature superconducting material (BSCCO) and a conventional superconducting material (Nb) terminated by the dielectric cap layer. The investigated numerical results are essentially based on the basics of the transfer matrix method and the two-fluid model. The numerical results showed the appearance of two sharp peaks, which are referred to Fano and electromagnetic-induced reflectance resonances. Also, we demonstrate the effects of many parameters on the reflectance properties of Fano resonance and the electromagnetic-induced reflectance. The effects of the constituent layer thicknesses, the number of periods, the operating temperature, the angle of incidence, and the refractive index of the dielectric cap layer are all considered. Finally, the effects of hydrostatic pressure on the Fano and EIR resonances are studied and calculated. This structure can play an important role in optical switching devices. [ABSTRACT FROM AUTHOR]

Abstract: We theoretically studied electromagnetic wave propagation in a one-dimensional metal/dielectric photonic crystal (1D MDPC) consisting of alternating metallic and dielectric materials by using the transfer matrix method in visible and infrared regions. We have investigated the photonic band gap by using four kinds of metals: silver, lithium, gold and copper. We discuss the details of the calculated results in terms of the thickness of the metallic layer and different kinds of metals, and the plasma frequency. Our results have a potential for applications in optical devices because it is easy and cheap to manufacture. [Copyright &y& Elsevier]

In this work, we propose a heterostructure of different photonic crystal designs for multi passband filter applications at THz region. The suggested heterostructure is composed of regular photonic crystal (PC) designs and quasi-periodic photonic crystal (QPPC) of Fibonacci sequence. In our study, the QPPC is inserted between the two regular PC designs. By using the well-known transfer matrix method (TMM), we theoretically investigated the interaction of the incident electromagnetic waves with the proposed PC heterostructure. The numerical results demonstrate resonant peaks appeared in the transmittance spectrum of the proposed design. The tunability feature of the resonant peak is presented by controlling some of the design parameters such as the periodicity number of Fibonacci sequence value and the thickness of the constituent layers. In addition to that, we demonstrated the effect of the hydrostatic pressure on the resulted resonant peaks and the transmittivity of the proposed filter as well. The tunability feature of the resulted resonant peaks make our proposed filter act as multi passband filter via controlling the design parameters at the THz region. [ABSTRACT FROM AUTHOR]

This work assesses the dependence of the refractive index of a one-dimensional photonic crystal composed of SiO 2 and Si on its applied pressure. Therefore, the Transfer Matrix Method is used to calculate its transmittance spectrum. After breaking the structure periodicity, we found the photonic band gaps of a defect mode, which may be tuned by increasing the external pressure applied. In addition, we reported that when increasing pressure, and depending on the layer arrangement within the crystal, we can maximize the energy stored by the defect mode through quality factor measurements. [ABSTRACT FROM AUTHOR]

In this study, we calculate the transmittance spectrum of a one-dimensional photonic quasicrystal composed of SiO 2 and an extrinsic InSb semiconductor. The layers of materials are arranged as per the Octonacci sequence. When using the transfer matrix method, the transmittance spectrum is tuned, by a variation in the temperature, the doping concentration, and the thicknesses of materials. At fixed values of the Octonacci sequence, we find that the fractal photonic band gap and the quasi-localized states exhibit a shift to higher frequencies when temperature increases. The blue-shift of the transmittance spectrum is obtained when the doping concentration is increased. [ABSTRACT FROM AUTHOR]

In the present study, we have theoretically proposed a novel sensing tool based on a polymer defective one dimensional photonic crystal for highly accurate and sensitive pressure detection. The strain sensitive refractive indices of photonic crystals constituent materials have been considered to realize a pressure sensor device. The strain sensitive refractive index contrast is the main factor to achieve the goal. The numerical results satisfy significant changes in the refractive indices of these materials with applied hydrostatic pressure. Therefore, the sensitivity of the resonant mode that formed inside the photonic bandgap is very high to the pressure changes. Moreover, the optimization of the parameters of the one dimensional photonic crystals constituent materials such as the angle of incidence, number of layers and thickness of the defect polymer layer has been analyzed to investigate the most possible performance. By using an optimizing process, we have investigated a relatively high sensitivity of the proposed sensor that could reach 21.16 THz/GPa or 199.66 nm/GPa. • Our study presents a novel sensing tool using a 1D PC for highly accurate and sensitive pressure detection. • The numerical results are investigated based on the transfer matrix method and the strain sensitive refractive. • Our design is based on materials of highly strain sensitive refractive indices such as Si, SiO 2 and Polystyrene (PS). • Our sensing tool can provide a sensitivity of 21.16 THz/GPa or 199.66 nm/GPa. • The investigated results for our pressure sensing device is much better than the works reported. [ABSTRACT FROM AUTHOR]

• We study the transmittance spectrum in Rudin Shapiro quasiperiodic one-dimensional photonic crystals composed by a superconducting material and semiconducting material. • We have demonstrated that as the pressure increases, the defect modes shift to higher frequencies in the frequency domain. • When the thickness of the semiconductor layers increases, more splitting is observed in the transmittance peaks. The present paper determines the properties of the transmission spectrum in a quasi-periodic one-dimensional photonic crystal. The photonic crystal is composed of a high-temperature superconductor (HgBa 2 Ca 2 Cu 3 O 8 + δ ) and a semiconductor (GaAs). These materials are arranged based on the Rudin Shapiro sequence. Additionally, this study also considers the effects of temperature and pressure on the optical properties of the superconductor and semiconductor. Using the transfer matrix method and the two-fluid model, this study finds that when the sequence increases, the transmittance peaks split also increases. When the temperature rises at fixed pressure and sequence values, the transmittance spectrum denotes defective modes within the photonic band gap. The same behavior is observed as the pressure increases, while the transmittance spectrum noticeably shifts toward higher frequency regions. Finally, when the thickness of the semiconductor layers increases, more splitting is observed in the transmittance peaks than when we increase the thickness of the superconducting layers. We expect this paper to provide a pathway to design optical filters based on quasi-periodic superconductor photonic crystals. [ABSTRACT FROM AUTHOR]

In this research, the hydrostatic pressure effects on the transmission spectra of a one-dimensional (1D) defective phononic crystal (PnC) are calculated and studied. The transmission spectra of the defective PnC are calculated based on the transfer matrix method (TMM). To measure the hydrostatic pressure efficiently, a pressure-sensitive material such as Poly (methyl methacrylate) (PMMA) is proposed as a defect layer. Thereby, the proposed PnC structure is designed from silicon (Si) and tungsten (W) according to the configuration [(Si/W)2 PMMA (Si/W)2]. The numerical results show the appearance of a localized resonant mode through the transmission spectra. A wide pressure range from 0 GPa to 10 GPa is considered on the PnC transmission spectra and the localized resonant mode as well. Remarkably, any increase in the hydrostatic pressure value resulted in the displacement of the resonant mode towards the higher frequencies with a significant increase in its intensity as well. The effect of the PMMA thickness on the number of resonant modes is studied as well. Moreover, the proposed PnC design showed high performance for hydrostatic pressure sensing represented by the high sensitivity and Q-factor values of 556,300 Hz/GPa and 3660, respectively. We expect this design to attract the researchers' attention to hydrostatic pressure influences that may affect different PnC designs and applications. • A highly sensitive 1D defective PnC design is proposed to sense and measure hydrostatic pressure. • The PnC structure from a multilayer of silicon and tungsten with PMMA as a defect layer. • The proposed sensor showed high performance and quality factor versus a wide range of pressure. • The PnC design has a sensitivity of the value 556,300 Hz/GPa and Q-factor of 3660. [ABSTRACT FROM AUTHOR]

In this research article , we present theoretical and numerical investigations concerning the effects of temperature on the transmittance properties of one dimensional annular photonic crystals. The theoretical basis of our study adopts the modified transfer matrix method applied to optical fiber waveguides. The numerical results showed many features that could be of interest. In this regard , we investigate this design to enhance the values of sensitivity based on its geometry. Our design exhibits a remarkable response to temperature changes with a sensitivity of about 0.033 nm/°C which is considered significantly high. Also, it is found that the upper edge of the photonic band gap increases considerably with temperature changes, while the lower edge is almost unchanged. The effects of the core radius and number of periods on the transmittance of our annular photonic crystals design have been also investigated. It is found that an appropriate choice for the core would give flexibility of fabrication and stability of transmission output. In addition, this study reveals that the phase shift of the reflected cylindrical waves within the core is strongly dependent on temperature. We believe our structure is potentially promising in designing and fabrication of novel high-performance temperature sensors and integrated waveguide devices such as optical switches and filters. • The effect of temperature on transmittance properties of 1-D annular PCs comprising Si and SiO 2 layers is demonstrated using the modified transfer matrix method. • Numerical results reveal a significant change in both the photonic band gap width and in the spectral location of the transmittance spectrum with temperature changes. • A perceptible sensitivity of 0.033 nm C−1 has been achieved which is much higher than the sensitivity of planar PC temperature sensors. • Using monochromatic light, the proposed structure acts as a very efficient sensor depending on changes occurring in maximum transmittance. • Appropriate control of the core radius could offer flexibility of fabrication and stability of transmittance behavior. [ABSTRACT FROM AUTHOR]

In this research article, we have theoretically introduced a one-dimensional topological photonic crystal (1D TPC) design to provide a better stability due to imperfections and fluctuations in geometry compared to the traditional PC structures. The considered structure is designed by the combination of two different PCs, i.e., PC 1 and PC 2. PC 1 consists of two layers of silicon (Si) and magnesium fluoride (MgF 2), while PC 2 contains a multilayer stack of MgF 2 and hyperbolic metamaterial (HMM). Interestingly, the HMM layer is introduced as a composite of a dielectric material of indium arsenide (InAs), and nanocomposite of Ag nanoparticles inside a hosting medium of Y 2 O 3. The foundations of our theoretical framework are based on Effective Medium Theory (EMT), the Transfer Matrix Method (TMM), and the Maxwell-Garnett model. Our research primarily focuses on utilizing our design as a pass/stop band filter for near-infrared (NIR) applications. Notably, this proposed design exhibits significant stability in the face of imperfections and variations. Our numerical findings highlight the influence of several geometric parameters including the refractive index of hosting medium for Ag nanoparticles, thicknesses, and filling fraction on the characteristics of the resulting filter. Remarkably, the results also reveal the emergence of multiple resonance peaks that maintain high stability against geometric tolerances. We believe our work presents a finite photonic crystal (PC) whose wave localization properties are resilient to random geometric imperfections, making it suitable for NIR filtering applications. • We have introduced a one-dimensional topological photonic crystals as a novel design with high stability. • Our design is basically consisting of two different types of photonic crystals namely, PC 1 and PC 2. • The structure can be used as a combination pass/stop band filter, especially for near-infrared (NIR) applications. • The numerical findings demonstrated the formation of many resonance peaks with high stability against geometrical tolerance. • This work introduces a novel photonic crystal whose properties are robust against random geometrical imperfections. [ABSTRACT FROM AUTHOR]

In this research, we have theoretically introduced a new application of one-dimensional (1D) phononic crystals (PnCs) manifested as a sensor for the variations in porosity ratios of a high T c superconductor material (Ba 2 Cu 3 O 7-δ). Notably, there is a massive need for accurate detection of the changes in the porosity ratio of the YBa 2 Cu 3 O 7-δ material due to the dependence of its resistivity and critical current density J c as well on the porosity ratio. Meanwhile, the changes in the porosity ratio could be demonstrated by tuning a resonant mode in the transmission spectrum of the 1D PnC. Therefore, we considered the YBa 2 Cu 3 O 7-δ as a defect layer inside the periodic design (Lead/Epoxy)N of the 1D PnC. Herein, the transfer matrix method (TMM) is used to calculate the transmission spectra of the proposed design. Our findings showed that the proposed sensor is capable of detecting and sensing the variations in the porosity ratio of YBa 2 Cu 3 O 7-δ as well as indicating its mechanical properties with relatively high performance and sensitivity. Moreover, the obtained results have unfolded a very sensitive effect in the resonant peak position based on the physical properties of YBa 2 Cu 3 O 7-δ. Since the position of the resonant peak is highly sensitive to the smallest changes in the porosity ratio. Finally, the investigated sensitivity and quality factor can reach the values of 75.04 kHz and 186.474, respectively, for a 1% change in the porosity of YBa 2 Cu 3 O 7-δ. In a nutshell, it's a new way of correlating the mechanical properties of a porous high T c superconducting material based on the porosity ratio that may be used in various industrial and technological applications. [ABSTRACT FROM AUTHOR]