2D PhC Research Articles

Enhanced Sensing of Diseased Blood Samples through One-Dimensional MgO-SiO2 Photonic Crystal Sensor

In this investigation, we present a tailored one-dimensional photonic crystal sensor (1D PCS), magnesium oxide (MgO) and silicon dioxide (SiO2) layers designed for the specific detection of diseased blood samples components, including plasma, platelets, red blood cells, and uric acid concentrations. The sensor structure is architecturally optimized for 6, 8,10,12,14, and 20 periods, encapsulating a central defect cavity that facilitates the interaction with the blood samples. Upon introducing the blood samples into this cavity, the transmittance spectrum is meticulously analyzed using the transfer matrix method to observe the variations in the defect mode’s wavelength. The study is conducted over a range of incident waves from wavelength 450 to 750 μm, enhancing the understanding of the sensor’s effect on the detection mechanism. In this context, our sensor demonstrates a remarkable sensitivity of approximately 815 nm per refractive index unit (RIU-1). It achieves a detection limit of 10–5, showcasing an exceptional ability to detect low concentrations of the infected blood components.Moreover, Q Factor of 3795 and FOM of 3369.18 indicate the sensor’s high precision in differentiating between healthy and infected blood samples.These findings underscore the potential of the proposed MgO-SiO2-based 1D PhC sensor in serving as a high-fidelity tool for biosensing application.

Ultra-sensitive Two-dimensional Photonic Crystal Biosensor for Oral Cancerous Cell Detection

Background & Objectives: Over the past two decades, biophotonic sensors based on two-dimensional (2D) photonic crystals (PhCs) have garnered significant attention in cancer diagnosis. This technology has become a crucial tool in early cancer detection and treatment response monitoring due to its ability to detect minute changes in biomarker concentrations and molecular interactions. The development of these sensors through advanced nano and microfabrication techniques has significantly improved diagnostic accuracy and speed, promising substantial enhancements in therapeutic outcomes for cancer patients. Materials & Methods: A biosensor based on a 2D PhC was designed and simulated for the detection of oral cancer cells in a sample. The biosensor, structured with silicon rods in air using the Finite-Difference Time-Domain tool, utilizes five rods as an analyte for detecting normal and cancerous cells, thereby evaluating the sensor’s performance. Results: The variation in the transmission spectrum was studied to detect the presence of malignant cells in the test sample. The sensor’s structural parameters were carefully adjusted to enhance its sensitivity, a crucial factor in the accurate detection of cancerous cells. Two critical parameters, Q-factor and sensitivity, were derived from the results. The sensor achieved a sensitivity of 1148 nm/RIU with a Q-factor of 193. Conclusion: The designed biosensor demonstrates superior accuracy and sensitivity in identifying both malignant and normal cells in the test sample, making it suitable for real- time deployment in point-of-care applications.

Enhancement of Light Efficiency of Deep-Ultraviolet Light-Emitting Diodes by Encapsulation with a 3D Photonic Crystal Reflecting Layer.

Recently, UVC LEDs, which emit deep ultraviolet light, have found extensive applications across various fields. This study demonstrates the design and implementation of thin films of three-dimensional photonic crystals (3D PhCs) as reflectors to enhance the light output power (LOP) of UVC LEDs. The 3D PhC reflectors were prepared using the self-assembly of silica nanospheres on a UVC LED lead frame substrate via the evaporation-induced method (side) and the gravitational sedimentation method (bottom), respectively. These PhCs with the (111) crystallographic plane were deposited on the side wall and bottom of the UVC LED lead frame, acting as functional materials to reflect UVC light. The LOP of UVC LEDs with 3D PhC reflectors at a driving current of 100 mA reached 19.6 mW. This represented a 30% enhancement compared to commercial UVC LEDs with Au-plated reflectors, due to the UVC light reflection by the photonic band gaps of 3D PhCs in the (111) crystallographic plane. Furthermore, after aging tests at 60 °C and 60% relative humidity for 1000 h, the relative LOP of UVC LEDs with 3D PhC reflectors decreased by 7%, which is better than that of commercial UVC LEDs. Thus, this study offers potential methods for enhancing the light output efficiency of commercial UVC light-emitting devices.

Design of a 1D PhC biosensor with enhanced sensitivity based on useful features provided for the detection of waterborne bacteria

In this article, we propose a one-dimensional photonic crystal (1D-PhC) biosensor design to detect water-borne bacteria such as Shigella, Vibrio cholera, Salmonella, and E. coli. The theoretical reflectance spectrum of a 1D-PhC and the sensitivity of types of bacteria such as Shigella flexneri, Salmonella, E. coli, and Vibrios cholera are investigated by using the transfer matrix method and MATLAB software. The impact of incident angle and central wavelength on the performance and sensitivity of biosensors are studied. The suggested sensor's sensing process is dependent on variations in the refractive indices of different species of bacteria. The variation in the central wavelength, angle of incidence, the sensitivity of the proposed structure, and other parameters such as full width at half maximum, quality factor, damping ratio, and detection limit can be enhanced. The obtained average sensitivity of our design has a value of 4073 nm/RIU at optimum conditions of defect layer thickness and incident angle. Also, the proposed biosensor design exhibits a high quality factor value of 10996.2165 and a low detection limit value of 0.44607×10-5\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$0.44607 \ imes \\,10^{ - 5}$$\\end{document} RIU.

Sequential infiltration of two-photon polymerized 3D photonic crystals for mid-IR spectroscopic applications

Photonic crystals (PhCs) are spatially organized structures with lattice parameters equivalent to the operational wavelength of light. PhCs have been subject to extensive research efforts in the last two decades and are known for controlling light propagation with applications in sensing and time-delayed communication due to the slow-light phenomenon. Despite their exceptional properties, PhCs are difficult to fabricate using planar micromachining techniques due to their periodic structures. Techniques like two-photon stereolithography have been discussed for PhC fabrication in the literature, but the inherent disadvantage of poor refractive index (RI) contrast results in limited application. In this work, we present sequential infiltration synthesis performed on two-photon stereolithographically printed 3D PhCs for infiltration with zinc oxide to increase the RI of 3D PhCs. Finite element analysis was performed over a range of RI contrast values to study the change in photonic bandgap (PBG) with RI contrast. The transmission spectra were recorded on 3D PhCs before and after infiltration to demonstrate the change experimentally. An increase in the PBG width and absorbance is seen postinfiltration due to enhanced RI. This work presents the first, to our knowledge, sequentially infiltrated enhanced 3D PhC fabricated with two-photon stereolithography.

Research on the Development of New Sensors and Sensor Detection Technology in the Context of Big Data

Abstract In the context of big data, traditional detection algorithms can no longer meet today’s needs. For traditional sensors, there are shortcomings such as long working times, high complexity, and high false detection rates. This paper proposes a new type of sensor and an algorithm for detecting anomalies in sensors based on Flink. The sensor network senses the monitoring targets in the monitoring area in real time and transmits them to the end users through wireless communication. Then, the fusion rule for target detection in sensor networks is studied. Then, the detection algorithm is computed using Flink and predicted using a sliding window and ARIMA model on the Flink platform. Then, the confidence intervals of the prediction results are calculated, and the outliers are evaluated. Finally, the K-Means++ algorithm is used for clustering and probability assessment of previously obtained outliers. Then, compared with traditional sensors, comparative analysis shows that the proposed method in this paper has some advantages in terms of both sensitivity (S) and quality factor (Q). The value of S is more than 320 than the 2D PhC sensor array. The value of Q is more than 5295 than the 2D PhC sensor array. This paper’s new sensor detection method is more diverse than the traditional method. The detection time is reduced. The detection accuracy is also improved compared to the traditional method. It can be summarized by comparison that the new sensor in this paper is more excellent than the traditional method of detection.

Nearly Perfect Spin Conversion Based on Topological Singularity in 1D Anisotropic Photonic Crystals

AbstractAlthough the spin‐controlled vortex generation and photonic spin‐Hall effect of spin‐flipped abnormal mode have been widely studied recently, the traditional method based on the metasurface is difficult to fabricate, and the efficiency of the spin‐flipped abnormal mode is rather low due to process errors and intrinsic material loss. Here, a new method is proposed based on the insights into the topological singularity and special Bragger reflections resonant (BRR) mode of one‐dimensional (1D) finite photonic crystals (PhCs) with anisotropic material to realize nearly perfect (100%) spin‐conversion efficiency. For a finite 1D PhC with cell number N, there are 3N complete spin‐conversion (CSC) and complete spin‐maintained (CSM) channels. Two mechanisms of these CSC and CSM channels are revealed. The working bandwidths and the angular ranges of these CSC and CSM are also studied. Based on these theoretical findings, multi‐angles and multi‐frequencies perfect spin‐conversion (‐maintained) devices can be designed. At last, these theoretical results are confirmed by the numerical experiments based on finite‐difference time‐domain (FDTD) methods. This work paves the way to exploring the topological properties and polarization control of PhCs made of anisotropic dielectrics and provides a prospective method for the design of multi‐channels spin optical devices.

An aptamer-functionalized photonic crystal sensor for ultrasensitive and label-free detection of aflatoxin B1

As a novel optical responsive material, photonic crystal is a promising sensing material in the recognition and detection of small molecules. Herein, a label-free composite sensor for aflatoxin B1 (AFB1) based on aptamer-functionalized photonic crystal arrays was successfully developed. Three-dimensional photonic crystals (3D PhCs) with a controllable number of layers were produced by a layer-by-layer (LBL) approach, and the introduction of gold nanoparticles (AuNPs) facilitated the immobilization procedure of recognition element aptamers, thus creating the AFB1 sensing detection system (AFB1-Apt 3D PhCs). The sensing system AFB1-Apt 3D PhCs exhibited a good linearity in the wide range of 1 pg mL−1-100 ng mL−1 AFB1 with a limit of detection (LOD) of 0.28 pg mL−1. Furthermore AFB1-Apt 3D PhC was successfully applied in the determination of AFB1 in the millet and beer samples with good recovery. The sensing system performed ultrasensitive and label-free detection to the target, which could be further applied in the fields of food safety, clinical diagnosis or environmental monitoring, establishing an efficient and rapid universal detection platform.

Enhancing light extraction efficiency of GaN LED by combining complex‐period photonic crystals with doping

AbstractThe light extraction efficiency (LEE) of GaN‐based light‐emitting diodes (LEDs) was limited by intense total internal reflection and the photothermal effect. In order to solve this problem, a method to synergistically control the LEE of GaN‐based LEDs by ​​combining the complex‐period photonic crystals (PhCs) with M (M = Al, In) material doping is proposed. The forbidden band width of two‐dimensional (2D) PhC array, three‐dimensional (3D) LED model, M doping, and electromagnetic field distribution are investigated respectively. By doping the M, the LED emission wavelength range is regulated to achieve the dual‐band emission. Furthermore, a triangular complex‐period photonic structure is introduced to establish stacked or etched PhCs models. By combining the plane wave expansion and finite difference time domain algorithm, the structural parameters of PhCs and M concentration dependent LEE are investigated, and the electromagnetic field distribution is explored also. The results show that the optimal LEEs can be achieved are 19.08% and 13.96% for blue light and ultraviolet, respectively, which are larger than that of traditional flat‐panel LED (4%). This work provides theoretical results and technical support for the design of LEDs with high luminous efficiency.

Two-dimensional photonic crystals as selective filters for thermophotovoltaic applications.

The optical properties and performance of the two-dimensional photonic crystal (2D PhC) filters at normal incidence were simulated, and the best geometric parameters were obtained with the help of a global optimization program. The honeycomb structure has better performance, including high in-band transmittance, high out-band reflectance, and low parasitic absorption. The power density performance and conversion efficiency can reach 80.6% and 62.5%. Furthermore, the deeper cavity structure and multi-layer structure were designed to improve the performance of the filter. The deeper one can reduce the influence of transmission diffraction, increases the power density performance and conversion efficiency. The multi-layer structure reduces the parasitic absorption significantly and increases the conversion efficiency to 65.5%. These filters have both high efficiency and high power density, avoid the challenge of high-temperature stability faced by emitters, also easier and cheaper to fabricate compared to the 2D PhC emitters. These results suggest that the 2D PhC filters can be used in thermophotovoltaic systems for long-duration missions to improve the conversion efficiency.

Tunable Fano resonance in coupled topological one-dimensional photonic crystal heterostructure and defective photonic crystal

In this paper, we theoretically investigate the transmission properties of a structure composed of a topological one-dimensional photonic crystal (1D PhC) heterostructure and a conventional 1D PhC containing indium-antimonide (InSb) as a defect layer using the transfer matrix method. The phenomenon of Fano resonance can be achieved by coupling the defect mode with the topological edge state mode, which is supported by the topological PhC. The numerical results show that a narrow Fano resonance is observed in the transmission spectrum of the structure in the presence of the external magnetic field applied to the InSb defect layer. The optical properties of the InSb defect layer, and, therefore, the Fano resonance, can be dynamically controlled by changing the applied external magnetic field. The results obtained with the proposed structure reveal that the magnetic field has the greatest influence on controlling the optical properties of the Fano resonance. These findings could be beneficial for optical devices such as optical filters, sensors, and optical switches.

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.

Silicon/graphene–ITO multiple heterojunctions and 1D PhC waveguide-based photodetection for mid-NIR IPE with high responsivity

A nanophotonic photodetector is proposed with a multi-heterojunction structure based on silicon–ITO (Indium Tin Oxide) slot waveguide covered with 2D (two-dimensional) graphene sheets. A heavily n-doped ITO layer covers the whole device and works as an electrode to reduce the light loss at the metal–graphene interfaces. Different waveguides are arranged to design a one-dimensional photonic crystal (1D PhC) and the slot is defined by creating a defect in it. The PhC provides strong confinement of light, increasing the light–matter interaction, and thus generating more electron–hole (e–h) pairs or charge carriers under light illumination. Moreover, the multiple heterojunctions enhance the e–h generation and help enhancing the transportation of charge carriers. As a result, high photocurrent, fast response across a large bandwidth, strong electron-photon interaction, and also enhancement of photocarrier multiplications can be achieved. The photodetector realizes a photoresponsivity beyond 0.6 A/W at around 1550 nm wavelength. From 0.5 V–2 V of the bias voltage, the difference between the photocurrent and the dark current for the device with the PhC is more than 5 times that for the device without the PhC. Moreover, a 25 Gbit/s non-return to zero optical transmission is measured at 10 km transmission. The proposed device has diverse applications such as telecommunications, optical computing, interconnects, laser radar, lab-on-chip for sensing, and on-chip quantum photonics.

Low threshold optical bistability based on topological edge state in photonic crystal heterostructure with Dirac semimetal.

The special band structure of three-dimensional Dirac semimetal (3D DSM) makes it show strong nonlinear optical characteristics in the terahertz region, which provides a new way to develop terahertz nonlinear devices with low threshold. In this paper, we theoretically study the optical bistability (OB) of transmitted light in a multilayer structure with 3D DSM embedded in two one-dimensional photonic crystals (1D PhC). The topological edge state (TES) excited by the 1D PhC heterostructure significantly enhances the local electric field near the nonlinear 3D DSM, 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 106 V/m levels. Furthermore, the influences of the Fermi energy and thickness of 3D DSM and the angle of the incident light on the hysteretic behavior as well as the threshold of OB are clarified. 3D DSM-based optical devices with intrinsic OB provide a building block for future integrated optical and all-optical networks.

Construction and Research of Multiple Stimuli-Responsive 2D Photonic Crystal DNA Hydrogel Sensing Platform with Double-Network Structure and Signal Self-Expression.

The stimuli-responsive DNA hydrogel has attracted wide attention in the fields of chemical and biological sensing. However, it is still a challenge to integrate characteristics with low-cost, high mechanical strength, and signal self-expression into a DNA hydrogel simultaneously. Herein, a stimuli-responsive 2D photonic crystal double network DNA hydrogel (2D PhC DN-DNA hydrogel) sensing platform is developed via combining the signal self-expression of 2D PhC array with the selective recognition of polyacrylamide (PAM)/DNA DN hydrogel. The change of DNA configuration induced by specific target triggers the change of 2D PhC DN-DNA hydrogel volume, leading to a shift of the Debye diffraction ring diameter. In order to verify the feasibility of this strategy, the 2D PhC DN-DNA hydrogel with C-rich sequences is chosen as a proof-of-concept. The results indicate that the hydrogel has good detection performance for pH and Ag+/Cys. And the Debye diffraction ring diameter of the hydrogel is correlated with the concentration of the Ag+/Cys in the range of 0.5-20 μM. Compared with previously pure DNA hydrogel sensing platform, the 2D PhC DN-DNA hydrogel features low-cost preparation process and label-free determination. Meanwhile, only a laser pointer and a ruler are needed for the determination of targets, which shows that the hydrogel has application prospect in the development of portable response equipment.

Controlling the Bandgaps of One-Dimensional TiO<sub>2</sub>/SiO<sub>2</sub>, TiO<sub>2</sub>/SnO<sub>2</sub>, and SiO<sub>2</sub>/SnO<sub>2</sub> Photonic Crystals Using the Transfer Matrix Method

One-dimensional photonic crystals (1D PhCs) have a unique ability to control the propagation of light waves, however certain classes of 1D oxides remain relatively unexplored for use as PhCs. Specifically, there has not been a comparative study of the three different 1D PhC structures to compare the influence of layer thickness, number, and refractive index on the ability of the PhCs to control light transmission. Herein, we use the transfer matrix method (TMM) to theoretically examine the transmission of 1D PhCs composed of layers of TiO2/SiO2, TiO2/SnO2, SiO2/SnO2, and combinations of the three with various top and bottom layer thicknesses to cover a substantial region of the electromagnetic spectrum (UV to NIR). With increasing layer numbers for TiO2/SiO2 and SiO2/SnO2, the edges became sharper and wider and the photonic bandgap width increased. Moreover, we demonstrated that PhCs with significantly thick TiO2/SiO2 layers had a high transmittance for a wide bandgap, allowing for wide-band optical filter applications. These different PhC architectures could enable a variety of applications, depending on the properties needed.

Fabrication of three-dimensional photonic crystals for near-infrared light by micro-manipulation technique under optical microscope observation

We developed a micro-manipulation technique performed under optical microscope observation, which enabled the accurate fabrication of three-dimensional photonic crystals (3D PhCs) for near-infrared light. Thin GaAs plates having an array of rods were picked up with a fine needle by means of the van der Waals force and were mechanically stacked one-by-one by using vertical posts as guides. In spite of the limited spatial resolution in the optical microscope images, the mechanical resolution of the micro-manipulator and the precisely fabricated vertical posts enabled a stacking error that was an order of magnitude smaller than the period of the 3D PhCs. Photoluminescence measurement of a 3D PhC nanocavity containing quantum dots showed a cavity-mode peak in the near-infrared region.

Photonic crystal-based biosensor for detection of human red blood cells parasitized by plasmodium falciparum

In this paper, a biosensors based on a two-dimensional photonic crystal (2D PhC) waveguide including a ring resonator is designed and simulated based on refractive index changes of red blood cells. The proposed biosensor structure consists of an elliptical photonic crystal ring resonator and two linear waveguides containing silicon nitride rods in a 2D rectangular lattice with circular rods. The biosensor is utilized to detect the stages of the Plasmodium falciparum cycle in red blood cells and to diagnose malaria disease. The proposed design distinguishes with high sensitivity between normal red blood cells and cells infected with Plasmodium falciparum. This biosensor is very compact, consists of gold rods in the air background and works very well at two input central wavelengths of 0.514 and 1.55 μm. The finite-difference time-domain (FDTD) method is used to simulate and investigate the device. The biosensor is extremely compact which is very suitable for lab-on-chip applications and exhibits higher sensitivity at both input central wavelengths compared with that of previously reported sensors.

Investigating Fill Factor Effect on Brillouin Zone of Metamaterial-Based 2D Photonic Crystal

: Fill factor in the negative permittivity materials are tailored within the physically permissible limits to characterize the Brillouin zone for two-dimensional crystal under the propagation of both s and p-polarized waves. Two lowermost band-gaps are computed along with corresponding mid-band frequencies, where the plane wave expansion method is invoked for computational purposes. The rectangular geometrical shape is considered for the simulation, and all the results are calculated inside the ‘Γ’ point and ‘X’ point of the first Brillouin zone. Simulated findings depict monotonous variations of both band-gap width as well as mid-band frequency for higher negative permittivity materials, when the magnitude of fill factor is comparatively low, for both TE (Transverse Electric) and TM (Transverse Magnetic) mode of propagations. Lower negative permittivity leads to random fluctuations, which makes it unsuitable for photonic component design. Multiple forbidden regions may be observed for some specific artificial materials which can be utilized in the antenna or multi-channel filter design in higher THz region. Aims: The present paper aims to compute the shape of the first Brillouin zone from the fill factor for a two-dimensional photonic crystal structure. Background: EBG (Electromagnetic Bandgap) of a photonic crystal plays a major role in determining its candidature for optical applications, which is critically controlled by the fill factor. Therefore, it is significant to investigate the effect of F.F on the wave propagation characteristics of 2D PhC(Twodimensional photonic crystal). Objective: Investigation of metamaterial-based photonic crystal structure for electromagnetic band-gap analysis in the desired spectrum of interest as a function of fill factor inside the first Brillouin zone. Methods: Maxwell’s equations are solved using the plane wave propagation method to solve the problem, and simulation is carried out in MATLAB® software. Result: Both the first and second photonic band-gaps are simultaneously computed with a variation of refractive index differences of the constituent materials as well as with the fill factors. Results are extremely significant about the formation of narrowband and wideband filters on certain material combinations and structural designs. Conclusion: Better tenability is observed for metamaterial structure compared to conventional positive index materials, and fill factor has a great role in shaping the Brillouin zone and corresponding bandgap width.

Titanium nitride as a plasmonic material for excitation of Tamm plasmon states in visible and near-infrared region

In this study, I demonstrated the existence of Tamm plasmon polariton (TPP) modes at the interface of one-dimensional photonic crystals (1D PhC) and metal nitrides. Metal nitrides such as titanium nitride (TiN), zirconium nitride (ZrN), tantalum nitride (TaN), and hafnium nitride (HfN) exhibit metallic properties in the visible and infrared spectral ranges. Theoretical calculations were performed to evaluate TiN as an alternative plasmonic material to conventional plasmonic metals for the excitation of TPP modes in the visible and near-infrared spectral region. The transfer matrix method was used to study the proposed structure and its spectral properties. I also explored the suitable conditions for the efficient excitation of TPP modes with TiN as a plasmonic material. The optimum TiN thickness was investigated for TPP excitation in the visible and near-infrared spectral region. In addition, I explored the angular dispersion characteristics of the TPP modes in TiN-PhC configurations. The results obtained in this study may be useful for designing devices based on TPPs.