Dimensional Photonic Crystals Research Articles

Surface plasmon-like properties of one-dimensional photonic crystal and its application in surface-enhanced fluorescence

The present work reports on the plasmon-like properties of one dimensional photonic crystal (1D PhC) as active material for surface-enhanced fluorescence application. 1D PhC was prepared through layer-by-layer deposition of spin coated Poly (methyl methacrylate) and vacuum deposited As2S3. The thicknesses of the alternating layers were tailored with Bragg’s condition for a quarter wave stack. The optical properties of the 1D PhC were characterized by UV-Vis-NIR spectrophotometry. The interaction of surface electromagnetic waves (SEW) supported by the photonic crystals with the localized surface plasmon waves spreading on the surface of very thin metallic films deposited on top of the 1D PhC was investigated. The efficiency of the surface-enhanced fluorescence was studied by using a 0.1 % w/v Cu (II)-phthalocyanine (CuPc) in Pluronic PE 6800 water solution. Two times enhancement of fluorescence signal of CuPc was observed in the case of Au overlayer on the surface of the 1D PhC.

A combination of angle insensitive stopband/passband filters based on one-dimensional hyperbolic metamaterial quasiperiodic photonic crystals.

In the present work, we demonstrate the transmittance properties of one dimensional (1D) quasi-periodic photonic crystals that contain a superconductor material and a hyperbolic metamaterial (HMM). A HMM layer is engineered by the subwavelength undoped and doped Indium Arsenide (InAs) multilayers. Many resonance peaks with angle stability are obtained from the proposed Fibonacci sequence structure using the transfer matrix method (TMM). In this case, the Fibonacci sequence serves as the mainstay in the design of our structure. The permittivity of the utilized superconductor and the HMM are also analyzed, respectively. The numerical findings showed that the incident angle has no effect on the wavelength positions of the resonance peaks. The effects of many parameters such as the superconductor material thickness, Fibonacci sequence number, and sequence type are discussed for the proposed structure. At various operating temperatures and superconductor material types, the transmittance characteristics of the proposed structure were also examined. The designed structure can serve as a combination of pass/stop band filters for near-infrared (NIR) applications.

Transmission characteristics of DNA templated 1D photonic crystal system for 3D printing applications: Simulation

This paper discusses the novel features of DNA-templated one dimensional photonic crystals (1D PC) for additive manufacturing (AM) or 3D printing applications. AM applications utilize a variety of materials with tailored thermal, physical, chemical, and mechanical properties. However, the integration of optical properties into AM materials is less explored. AM parts produced from the materials having specific optical properties opens up many opportunities to develop novel integrated optoelectronic and photonic systems and provide sustainable structural color to the produced parts. This work proposes micro level periodic structures which can be used to replace existing color dyes for durable, non-toxic, cost-effective 3D printing applications. Based on ink jet printing technology, we designed DNA templated one dimensional (1D) photonic crystal (PC) of three-layer unit cell. The light transfer properties of the proposed 1D PC were examined theoretically in the range of 400 nm–800 nm of visible region of light using transfer matrix method (TMM). The photonic bandgap for DNA templated 1D PC is obtained around 450 nm and 650 nm of visible spectra region. The theoretical simulation shows that the presence of DNA template decreases the band gap width in the visible region and the three-layered periodic system helped to control the formation of multiple color bands in the visible region. The dispersion relation also confirmed that the electromagnetic fields in the stratified structure have been undergone multiple scattering and that results the formation of bandgap within the visible region. We also presented the standard deviation of the transmission coefficients in the range of 450 nm–650nm of visible spectra. Based on these observation and analysis, DNA templated PCs can be effective for tuning desired color spectra. Besides, this system can be used to replace the existing health hazardous synthetic dyes by incorporating with inkjet printing processes to create durable and colored 3D objects for aesthetic as well as technical purposes.

Mesogen-jacketed liquid crystal like block copolymers: synthesis and self-assembly to prepare 1D PC thin films

One dimensional photonic crystals (1D PCs) show great potential application in light control, sensors and functional displays. Self-assembly of block copolymer is a facile method to prepare 1D PCs in large area and easy processing. However, due to the low refractive index of polymer and the chain entanglement at very high molecular weight, it is difficult to prepare 1D PCs by self-assembly of linear block copolymers. In this work, mesogen-jacketed liquid crystals like block copolymers with two different lumbar connected benzene terephthalate derivatives and polynorbornene backbone are designed and synthesized. The big steric hindrance of the mesogenic benzene terephthalate derivatives extends the polymer backbone to be rigid, and the resultant block copolymers are rapidly self-assembled into lamellar structures with big domain spacing. The refractive indexes of the two blocks is differentiated by selecting the phenyl and decyl substitute group of benzene terephthalate derivatives. Hence, 1D PCs are prepared by self-assembly of mesogen-jacketed liquid crystals like block copolymers. The maximum reflectance is ranged from ultraviolet to near infrared by increasing the polymerization degree of the block copolymers from 400 to 1400 gradually. The lamellar structures are characterized by cross section scanning electron microscope and small angle X ray scattering. Mesogen-jacketed liquid crystal like block copolymer is favored in 1D PC preparation for its facile synthesis and flexible structure design.

(Invited) Broadband and Broad Angle Enhanced Light Absorption in MoS2 based Hetero Plasmonic Structure

Solar cells, photovoltaic devices and optoelectronic elements needs enhanced light absorption with a wide range of incident angle for better and efficient design. Two-dimensional (2D) materials have exceled in all areas including electrical applications, optical modulations, mechanical as well as chemical implementations due to their direct bandgap and high optical absorption nature[1]. Photon irradiation allows to generate electron-hole pairs in a direct bandgap material such as TMDCs which makes them potential candidates for large amount of light to be trapped. Different structures have been studied to achieve high optical absorption [2][3]. Although one dimensional photonic crystal(1DPC) and defective PC has good optical absorption with wide range and angle [4],[2] number of layers and complexity in structure has made it difficult to be fabricated. MoS2 monolayer structure based on cover spacer, plasmonic and dual substrate layer (SiO2(50nm)/Si ) has also increased optical absorption range and broad angle [5] but TMDC based heterostructures with spacer has improved absorption comparing to previous structures without metallic layer [6]. In this paper, we proposed a dual TMDC-spacer based plasmonic structure with dual substrate for wide and broad range and angle of near perfect optical absorption.The structure considered here is an air/MoS2/Spacer1/MoS2/Spacer2/plasmonic/dual substrate with 0.665nm, 70nm and 50nm layer of MoS2, Au as plasmonic layer and SiO2 as part of dual layer with Si as lossless substate. (Figure 1) For spacers SiO2 and TiO2 are taken with optimized value (figure 2) of 92 and 68nm for enhanced absorption. The transfer matrix of the constituted layer for either transverse electric (TE) or transverse magnetic (TM) polarization was determined using the transfer matrix method (TMM). Both in TE and TM mode, the ~30 and ~40% of enhanced light absorption are observed in proposed structure compared to hetero and mono layer structure (figure 3) with impact of metallic and spacer layer. In case of incident angle, both at resonance frequency of MoS2 and within visible range, broad angle range (00-400 for TE and 00-800 for TM) is observed with wider wavelength. (Figure 4 and figure 5). Impact of various metallic layer on the proposed structure is also observed (Figure 6). Structure with VO2 as plasmonic layer [7] has around ~95% of peak absorption (400nm-550nm) and wide incident angle (00-850) irrespective of polarizations with lieu of spacer hetero-TMDC-stack (Figure 7). Due to multiple layers of structures, collective surface plasmon polaritons (SPP) has an enhanced light absorption within the heterostructure and enhanced electric field distribution of the structure is observed (Figure 8).Table I lists some comparison among various structures and parameters indicates that proposed dual spacer -TMDC based plasmonic heterostructure has wide visible range of wavelength (400-550 nm) with broad angle (00-850) light absorption with both polarizations compare to other counterparts.In this work an enhanced range in both wavelength and incident angle of visible optical absorption is observed in both polarization with plasmonic dual heterostructure is observed and compared with other structures. Such structures are useful for photodetectors and solar cells for maximum absorptions.[1] Lopez-Sanchez O, Lembke D, Kayci M, Radenovic A and Kis A 2013 Ultrasensitive photodetectors based on monolayer MoS 2 Nat. Nanotechnol. 8 497–501[2] Ansari N and Mohebbi E 2018 Broadband and high absorption in Fibonacci photonic crystal including MoS2 monolayer in the visible range J. Phys. D. Appl. Phys. 51 149–52[3] Ansari N and Ghorbani F 2018 Light absorption optimization in two-dimensional transition metal dichalcogenide van der Waals heterostructures J. Opt. Soc. Am. B 35 1179[4] Ansari N and Mohebbi E 2016 Increasing optical absorption in one-dimensional photonic crystals including MoS2 monolayer for photovoltaics applications Opt. Mater. (Amst). 62 152–8[5] Ansari N, Mohebbi E and Gholami F 2020 Nearly perfect and broadband optical absorption by TMDCs in cover/TMDC/spacer/Au/substrate multilayers Appl. Phys. B Lasers Opt. 126 1–6[6] Ansari N, Goudarzi B and Mohebbi E 2021 Design of narrowband or broadband absorber by heterostructures including TMDCs and spacers Opt. Laser Technol. 138 106771[7] Das H R and Arya S C 2021 Performance improvement of VO2 and ITO based plasmonic electro-absorption modulators at 1550 nm application wavelength Opt. Commun. 479 Figure 1

Enhanced Temperature Sensing Based on the Randomness in the Multilayered 1D Photonic Crystals

A high sensitive temperature sensor is proposed based on the random properties of the one dimensional photonic crystal (1DPC). The structure is designed with two layers consisting of silicon (Si) and silica (SiO2) materials. The transmission spectra of the photonic crystals are studied at different temperatures from 25°C to 100°C. Thermal characteristics of the proposed random structures are examined with the effect of thermal expansion and thermo-optic effect. As the temperature increases the transmission peak shifts towards the longer wavelength due to the thermal parameters of the dielectrics used. It is found that the temperature-sensitive transmission peak shift is significantly improved due to the insertion of the third material that constitutes the ternary photonic structure (Si/SiO2/TiO2)N. For the above multilayer structures, based on the dependence of the layer thickness and the number of materials used, the numerical results show a sensitivity of 0.052nm/°C. When the third dielectric material (TiO2) is replaced by the polymer material (PS), the wavelength of the transmittance peak shift can be enhanced to 0.087nm/°C. These properties are useful for the fabrication of handy temperature sensors.

Detection of haemoglobin concentration in blood samples using nanophotonic biosensor

A biosensor device using one dimensional photonic crystal is designed for monitoring haemoglobin concentration in blood. Using the transfer matrix approach, the transmission spectra of a multilayered crystal structure (AB)7/ADA/(BA)7 is calculated. GaN is utilised as a media with a high refractive index (A), whereas air (B) is employed as a medium with a low refractive index. Here, defect layer (D) is chosen as blood sample. A resonant peak within photonic band gap can be shifted by a change in haemoglobin concentration in transmission spectrum. The sensor has the values of sensitivity, quality factor, figure of merit and detection limit as 439 nm/RIU, ~4.91×105, ~3.29×105/RIU and ~ 3.03 ×10-7 RIU respectively.

Pressure Dependent Characteristics of 1D Random Photonic Crystals

The effects of hydrostatic pressure on the defective random one dimensional photonic crystals (1DPC) were investigated for the two cases of polymeric materials. The polymers, Polystyrene (PS), and Polymethyl methacrylate (PMMA) act as the defect layer. Where the random structure is modeled with a combination of silicon and silica. The transmission spectra of the two multilayer photonic structures under pressure are analyzed using the transfer matrix method. The numerical results reveal a significant shift of localized states towards the shorter wavelength i.e., from 1550 to 1405 nm for the pressure range of 0-6 GPa. The localized states are very narrow which depends on the photoelastic relations between the selected materials. The sensitivity and R2 value obtained in PMMA inserted random structure is 29.5 nm/GPa and 0.959 respectively. When PMMA is replaced by Polystyrene, the sensitivity and the R2 value is improved to 35 nm/GPa and 0.987 respectively. These properties facilitate their applications in designing pressure sensors. The proposed configurations are physically realizable and versatile.

Design of ultra compact 4:2 encoder using two dimensional photonic crystals

In this paper all optical ultra compact 4:2 encoder is proposed and designed using two dimensional photonic crystals (PC). The proposed structure has silicon rods of refractive index 3.4 embedded in air host by creating line defects in hexagonal lattice platform. The analysis of the design is done for various experimental values of radius, lattice constant and pitch values using finite difference time domain (FDTD) and plane wave expansion (PWE) method of licensed OptiFDTD software tool. The structure is optimised to get maximum power confinement at the output of the two ports of the 4:2 encoder by inserting extra rods which interns acts like a resonator to couple the power to the two output waveguides. The structure is chosen in such a way that ( $$\frac{a}{\lambda }$$ ) will fall around 1550 nm wavelength only and is good for long distance transmission application as it is having low attenuation constant and high contrast ratio. Further, the proposed 4:2 encoder is operated at 1550 nm and it provides a high contrast ratio of 9.25 dB, propagation delay 33.1 fs and foot print of the structure is 119.34 $$\mu$$ m $$^2$$ . Hence it is highly advisable for photonic integrated circuits and optical signal processing.

High performance mid infrared temperature sensor based on resonance excitation of hybrid Tamm surface states

Theoretical design of mid infrared temperature sensor based on the resonance excitation of hybrid Tamm surface state (HTSS) is presented. An excellent sensing performance is attained by the coupling of graphene plasmon polaritons and hexagonal boron nitride (hBN) phonon polaritons that forms hybrid polariton modes at the interface. In one dimensional ternary photonic crystal (1D TPC), terminated by hBN layer sandwiched between graphene monolayers, the coupling between Bloch surface waves and hybrid polariton modes leads to the formation of HTSS or Tamm plasmon-phonon modes. Employing Kretschmann configuration coupling mechanism, the excitation of the HTSSs at the truncated interface is manifested for transverse magnetic (TM) polarized wave. The structure supports excited HTSS between 7.14μm to 10.34μm that allows astounding control over the sensing ability by varying the number of unit cells and the resonant angles. The sensor has a high detection accuracy of 1010 at room temperature (300K). It is proved that for 50 unit cells and at 49° angle, a high quality factor of 372176, detection limit of 5K and sensitivity of 0.20pm/K is attained with operating range between 280K to 380K. The operating range is widened from 300K to 900K by changing the resonant angle from 49° to 53°. Further, for 30 unit cells and at 53° angle, the temperature sensing ability of the sensor extends from 100K to 900K with a sensitivity of 0.80pm/K and detection limit of 54.16K.

Spontaneous emission enhancement based on thin-film chalcogenide/fluoride one dimensional photonic crystal

We report the fabrication of a one-dimensional photonic crystal microcavity via co-evaporation with electron beam/thermal evaporation process, which, to the best of our knowledge, is the first rare-earth doped one-dimensional photonic crystal based on chalcogenide/fluoride thin films. The microcavity was made of a half-wave dysprosium doped Ga2Se3 layer sandwiched between two embedded Ga2Se3/YF3 distributed Bragg reflectors. Near infrared transmittance spectra indicated that the stopband region from 1090 nm to 1515 nm was formed and a cavity resonance centered at 1342 nm. A cavity quality factor of 153 was achieved resulting in a 53-fold enhancement in spontaneous emission intensity. This photonic crystal microcavity configuration offers a new route to mid-wavelength and long-wavelength infrared fluorescence enhancement, which has attracted considerable interest for potential applications, such as fluorescence-based imaging and biomedical sensing.

Bio-Alcohol Sensor Based on One-Dimensional Photonic Crystals for Detection of Organic Materials in Wastewater

In this work, we have explored a novel application of one–dimensional (1D) photonic crystals (PCs) as a biomarker for the detection of organic materials in wastewater. The high concentration of organic materials may lead to adverse impact on human life. In order to save human life from these adverse effects, we have investigated the bio-alcohol sensing properties of a 1D multilayer periodic structure (AB)N/C/(AB)N capable of detecting organic materials in wastewater. The proposed structure works on the principle to detect a very small change in the refractive index of the wastewater sample under investigation by means of producing a shift in the position of the defect mode inside the photonic band gap (PBG) of the proposed structure. The transfer matrix method (TMM) has been used to investigate the transmission properties of the proposed design with the help of MATLAB software. We have also studied the effect of changes in the defect layer’s thickness, the volume fraction of the nanocomposite material and the incident angle on the sensitivity of our proposed bio-alcohol sensing design. Our bio-alcohol sensor shows a high sensitivity value of 500 nm/RIU and a low detection limit value of 1 × 10−5 RIU. The figure of merit and quality factor values of our bio-alcohol sensor are 5 × 103 and 5.236 × 103, respectively. The damping rate of the design is .

Wannier-function methods for topological modes in one-dimensional photonic crystals

In this work, we use Wannier functions to analyze topological phase transitions in one dimensional photonic crystals. We first review the construction of exponentially localized Wannier functions in one dimension, and show how to numerically construct them for photonic systems. We then apply these tools to study a photonic analog of the Su-Schrieffer-Heeger model. We use photonic Wannier functions to construct a quantitatively accurate approximate model for the topological phase transition, and compute the localization of topological defect states. Finally, we discuss the implications of our work for the study of band representations for photonic crystals.

Theoretical Studies of One Dimensional DNA Templated Silica/Metal Oxides, Graphite Oxide Photonic Crystals

We have designed one dimensional photonic crystals of Silica /Metal oxides (Alumina and ZnO), Silica/Graphite oxide on DNA template and investigated their optical responses in the 200 -2000 nm region of electromagnetic wave spectra theoretically using transfer matrix method (TMM). It is observed that in the presence of DNA template, the number, width and position of the photonic band gap are changed significantly. These results point that DNA templated proposed photonic crystals can be used for tuning the bandgap for desired spectra. This feature of DNA templated photonic crystals can be used for enhancing the transmission properties of photonic crystals. By tuning the bandgap effect for the desired frequency, the DNA templated photonic crystals can be applied for sensing the biomarkers. The theoretical results show that the DNA templated Silica based photonic crystals will be a promise for cost effective and fast responding label free biosensing applications.

Impact of arrangement, length and chemical potential on the robustness of graphene induced photonic bandgap in photonic crystals

The study of photonic crystals, artificial materials whose dielectric properties can be tailored according to the stacking pattern of their constituents, remains an attractive research area. Very recently, the propagation of light waves in periodic and quasiperiodic graphene embedded dielectric multilayers has also been considered. The presence of graphene between consecutive layers induces the emergence of the so-called graphene induced photonic bandgap. In this article, we employ a transfer-matrix treatment to study the effects of (i) random arrangement of the layers, (ii) length of the multilayer and (iii) chemical potential of graphene on the robustness of the graphene induced photonic bandgap (GIPBG) in one dimensional graphene-embedded photonic crystals. The photonic crystals considered here are composed of two dielectric materials, namely, silicon dioxide (layer A=SiO2) and titanium dioxide (layer B=TiO2). Our numerical results quantitatively show that the random arrangement and length of the multilayers cause minor changes in the bandgap edge of the low frequency GIPBG, i.e., the low frequency GIPBG is robust regarding composition and length of the structures. On the other hand, the chemical potential strongly affects the robustness of the low frequency GIPBG. In fact, the low frequency GIPBG is strongly dependent on the properties of graphene, reinforcing that it is possible to adjust its width and bandgap edge by tuning the chemical potential via a gate voltage.

Employing the Defective Photonic Crystal Composed of Nanocomposite Superconducting Material in Detection of Cancerous Brain Tumors Biosensor: Computational Study

The present research is focused on the externally tunable defect mode properties of a one dimensional (1D) defective photonic crystal (DPhC) for fast detection of cancerous brain tumors. The proposed design has utilized conventional 1D DPhC whose cavity is coated with SiO2 nanoparticles embedded in a superconducting material layer called a nanocomposite layer. The purpose of a nanocomposite superconducting layer is to induce temperature dependent external tuning of the defect mode inside PBG, in addition, to changing in the angle of incidence. The inclusion of a nanocomposite layer also improves the interaction between light and different brain tissue samples under examination. In order to investigate the transmission properties of the proposed structure the transfer matrix formulation in addition to the MATLAB computational tool has been used. First, we have chosen the optimized internal parameters at normal incidence to obtain the maximum performance of the design. Secondly, the effect of change in angle of incidence has been studied to further increase the performance by means of sensitivity, quality factor, the figure of merit and limit of detection to ensure external tuning of defect mode. After achieving a maximum value of sensitivity (4139.24 nm/RIU) corresponding to a sample containing a wall of brain tissues at θ = 63° we have further investigated the effect of change in temperature of nanocomposite layers on the position and intensity both of the defect mode inside PBG. We have found that the increase in temperature results in minute changes in sensitivity but a significant increase in the intensity of defect mode which is highly required in any photonic biosensing design. The findings of this study may be very useful for designing various bio-sensing structures which could have a significant and decisive role in the field of biomedical applications.

Propagation characteristics of transverse electromagnetic waves in a finite-size metallic superlattice of two alternating Al–Mg layers

Transfer matrix method has been used to investigate the propagation characteristics of a finite-size metallic superlattice. Wave reflectance, absorbance, and transmittance have been obtained for normally incident electromagnetic wave on a finite-size superlattice of two alternate layers of Aluminum and Magnesium. Such a periodic medium represents a simple model for a one dimensional photonic crystal. At low wave frequencies, the incident wave energy is shared between reflection and absorption with negligible transmission. Numerical calculations show a perfect absorption band for high number of unit cells N (above 100), which degrades as N decreases. The absorbance curves are interrupted by dips whose positions coincide with peaks in the reflectance curves along the wave energy axis. The reflectance profile revealed missing orders of reflection depending on the geometry of the superlattice. This is attributed to the excitation of interface plasmon modes that scatter incident radiation with wave vectors violating the Laue condition of diffraction. The reflectance is found to be well characterized by a finite number of unit cells for all wave energies. With increasing wave energy, the reflectance and the absorbance decrease and the superlattice becomes transparent in the high frequency range. Generally, the transmittance and absorbance characteristics of the superlattice were found to be strongly dependent on the number of unit cells of the superlattice under consideration. It has also been found that at high wave energies the superlattice becomes transparent; the real part of the input impedance approaches the vacuum impedance Z0 ​= ​377 ​Ω, while its reactance tends to zero.

Density of Bloch states inside a one dimensional photonic crystal

The density of Bloch modes inside a one dimensional photonic crystal (1D PC) is formulated based on its dispersion relations. This density function has applications in thermal emission inside a 1D PC, as well as controlling the dynamics of active materials embedded in them. After deriving the formulations, a practical 1D PC parameters in the visible range are used to calculate the density of transverse electric and transverse magnetic modes. Compared to the alternative methods such as using Dyadic Greens functions, this method is less complex and is exact. The method applies to any anisotropic medium for which the dispersion equations are available, analytically.

Solving Maxwell eigenvalue problems for three dimensional isotropic photonic crystals with fourteen Bravais lattices

In this paper, we present a unified finite difference framework to efficiently compute band structures of three dimensional linear non-dispersive isotropic photonic crystals with any of 14 Bravais lattice structures to a reasonable accuracy. Specifically, we redefine a suitable orthogonal coordinate system, and meticulously reformulate the Bloch condition for oblique Bravais lattices, and clearly identify the hierarchical companion matrix structure of the resulting discretized partial derivative operators. As a result, eigen-decompositions of discretized partial derivative operators and notably the discretized double-curl operator of any size, become trivial, and more importantly, the nullspace free method for the Maxwell’s equations holds naturally in all 14 Bravais lattices. Thus, the great difficulty arising from high multiplicity of zero eigenvalues has been completely overcome. On the basis of these results, we perform calculations of band structures of several typical photonic crystals to demonstrate the efficiency and accuracy of our algorithm.

Effects of Lattice Types on the Frequency Band Widths in Photonic Crystals

The plane wave expansion method was implemented in modeling and simulating the band structures of two dimensional photonic crystals (PhCs) with square, triangular and honeycomb lattices with circular air holes in dielectric or circular GaAs rods in air. The eigen value equation of TE and TM modes will presented. The Fourier transform of dielectric constant will analyzed and the effects of lattice type will discussed. The eigenvalue equations of TE and TM modes will solved using Matlab environment. Our results show that the first type of PhCs is more flexible than the second type in controlling the band widths and the achieved frequency positions, and the triangular lattice showed the greatest flexibility. On the other hand, this work showed the significant effect of the dielectric constant and the lattice constant on the achieved bandwidth.