Applications Of Photonic Crystals Research Articles

Limitations in design and applications of ultra-small mode volume photonic crystals

Ultra-small mode volume nanophotonic crystal cavities have been proposed as powerful tools for increasing coupling rates in cavity quantum electrodynamics systems. However, their adoption in quantum information applications remains elusive. In this work, we investigate possible reasons why, and analyze the impact of different low mode volume resonator design choices on their utility in quantum optics experiments. We analyze band structure features and loss rates of low mode volume bowtie cavities in diamond and demonstrate independent design control over cavity-emitter coupling strength and loss rates. Further, using silicon vacancy centers in diamond as exemplary emitters, we investigate the influence of placement imprecision. We find that the benefit on photon collection efficiency and indistinguishability is limited, while the fabrication complexity of ultra-small cavity designs increases substantially compared to conventional photonic crystals. We conclude that ultra-small mode volume designs are primarily of interest for dispersive spin-photon interactions, which are of great interest for future quantum networks.

Three-Dimensional Photonic Crystals Based on Porous Anodic Aluminum Oxide.

Photonic crystals (PCs) consisting of a periodic arrangement of holes in dielectric media have found success in light manipulation and sensing. Among them, three-dimensional (3D) PCs are in high demand due to their unique properties originating from multiple photonic band gaps (PBGs) and even full ones. Here, 3D PCs based on porous anodic aluminum oxide (AAO) were fabricated for the first time. Our approach involves prepatterning of the aluminum surface by a focused ion beam to form a hexagonal array of pore nuclei. Subsequent anodization in 1 M H3PO3 using a sine wave profile of voltage provides AAO with a defect-free in-plane porous structure and out-of-plane porosity modulation. The ability to tune the position, width, and depth of the PBGs is demonstrated. The combination of the flexibility of the proposed approach with the unique properties of AAO extends the range of practical applications of 3D PCs far beyond the current achievements.

Photonic crystal-coupled enhanced steering emission: A prism-free, objective-free, and metal-free loss-less approach for biosensing

Diagnostic assays utilizing fluorescent reporters in the context of low abundance biomarkers for cancer and infectious disease can reach lower limits of detection through efficient collection of emitted photons into an optical sensor. In this work, we present the rational design, fabrication, and application of one-dimensional photonic crystal (PC) grating interfaces to accomplish a cost-effective prism-free, metal-free, and objective-free platform for augmentation of fluorescence emission collection efficiency. Guided mode resonance (GMR) of the PC is engineered to match the laser excitation (532 nm) and emission maximum (580 nm) of the radiating dipoles to arrive at optimized conditions. The photo-plasmonic hybrid nano-engineering using silver nanoparticles presented >110-fold steering fluorescence enhancement enabling placement of the sample between the excitation source and detector that are in a straight line. From the experimental and simulation inferences, we propose a radiating GMR model by scrutinizing the polarized emission properties of the hybrid substrate, in accordance with the radiating plasmon model. The augmented fluorescence intensity realized here with a simple detection instrument provides sub-nanomolar sensitivity to provide a path toward point-of-care scenarios.

Regulating two-dimensional colloidal crystal assembly through contactless acoustic annealing

Two-dimensional colloidal crystals assembled from polystyrene nanospheres have emerged as a pivotal foundation for fabricating large-area nano-functional surfaces. These assemblies, defined by their hexagonal close-packed configuration and interlaced with grain boundaries, have garnered significant attention for applications in plasmonic structures, catalysts, photonic crystals, and inverse opals. Nonetheless, achieving consistent large-scale regularity has proven challenging due to unpredictable crystal growth and the introduction of defects. Utilizing acoustic waves excited from the airside, our experiments demonstrate the significant effects of such waves on the self-assembly process, leading to larger crystal domains and reduced defects. In comparison to the extensively studied water-end excitation techniques, our air-end excitation method introduces a novel dynamic in regulating colloidal monolayer crystallization and presents a comprehensive analysis of varying acoustic parameters, frequency, amplitude, and waveform. These findings reveal the potential of airside acoustic annealing in refining the structure of two-dimensional colloidal arrays. To elucidate our experimental observations, we delve into the theoretical underpinnings of particle dynamics, driven by classical hydromechanical constraints like surface tension and gravity. Using a qualitative estimate, we shed light on the resonant excitations and their potential role in optimizing the self-assembly process, especially focusing on resonances pertinent for enhancing cluster enlargements. Conclusively, our research, steeped in robust theoretical frameworks and groundbreaking experimental techniques, offers a multifaceted solution for perfecting two-dimensional colloidal arrays. This combined approach not only broadens the scope of acoustically induced crystallization but also charts a path for its adoption across diverse environments, signaling transformative prospects for nanomanufacturing and optical research.

Photonic crystal and Ti nanoparticles enhanced high-absorption GaAs thin-film solar cell

The research aims to investigate the application of photonic crystals and metal nanoparticles in the design of thin-film solar cell (TFSC). The propagation of electromagnetic waves in the vicinity of the cell and the light absorption process were simulated to analyze the performance variations of GaAs TFSC combining GaAs photonic crystals and Ti nanoparticles. By optimizing the cell model structure and doping concentration, we achieved high absorption across a broader wavelength spectrum. The research indicates that the incorporation of photonic crystals effectively extends the optical path length within the solar cell, while the integration of metal nanoparticles further enhances the cell's light absorption efficiency. Ultimately, the cell model proposed in this article achieves efficient light absorption in the wavelength range of 400–860 nm, with the absorption rates of the cell consistently exceeding 90% across all spectral bands. And nearly perfect absorption is realized in the wavelength range of 728–860 nm. Simultaneously, the performance of the cell exhibits significant improvements, culminating in a photoelectric conversion efficiency (PCE) of 34.48%. This research provides useful guidance for the development of solar cell technology and makes a positive contribution to the sustainable utilization of clean energy.

Quantitative Evaluation of the Relationship between Strain and Color Change in Opal Photonic Crystal Films and Application into Complex Specimen Geometries

The color change of opal photonic crystal films (OPCFs) due to deformation was quantitatively evaluated using digital image correlation (DIC) analysis. OPCFs were pasted on specimens of three different gauge geometries, and random patterns were formed on the opposite side of each specimen for DIC analysis. To assess the applicability of using OPCFs-based strain characterization for analyzing steel structural components and associated metallurgical analyses, smooth, width-gradient, and holed specimens were prepared in this study. As deformation increased in the smooth specimen, the color of the OPCFs changed significantly. The color change in the OPCFs could be quantitatively converted into strain values through Hue value analysis. Heterogeneous strain distributions could also be quantitatively analyzed using OPCFs-based analysis at the submillimeter or millimeter scale. When the strain gradient is too high, for example, near a stress concentration site such as a hole, local peeling of the OPCFs away from the specimen surface can occur. Consequently, for quantitative characterization, we must take proper care when measuring this upper limit of the “strain gradient” as well as strain, which would depend on the adhesion and surface condition of the specimen.

Spontaneous formation of liquid-crystalline nuclei in blue-phase liquid crystals based on different chirality

The self-assembly of three-dimensional nanostructures of blue-phase liquid crystals is becoming the spotlight of soft matter research and has potential applications in photonic crystals, sensors, electro-optic devices, and others.

Terahertz gas sensor and its application in gas detection of power pipe gallery

During the operation of a power cable duct, the content of flammable gas is an important element in the safety of the cable duct. The accurate detection and location of gas in the pipeline corridor are important to improve the safety and stability of the power system. In view of the change of the refractive index of the gas in the power cable tube gallery, this paper presents the important application of terahertz one-dimensional photonic crystals with high-quality factors in gas sensing, change of the gas refractive index in the tube gallery simulated, and the gas refractive index change in the tube gallery can be obtained accurately by analyzing the change of transmission peak at terahertz range, the potential of terahertz sensor in gas detection in power tube gallery is verified.

Application of Photonic Crystals for the Generation of Broadband Radiation at the LINAC-200 Linear Accelerator

Application of Photonic Crystals for the Generation of Broadband Radiation at the LINAC-200 Linear Accelerator

Coherent perfect absorber and laser induced by directional emissions in the non-Hermitian photonic crystals

In this study, we propose the application of non-Hermitian photonic crystals (PCs) with anisotropic emissions. Unlike the ring of exceptional points (EPs) found in isotropic non-Hermitian PCs, the EPs of anisotropic non-Hermitian PCs appear as symmetrical lines about the Γ point. The formation of EPs is related to the non-Hermitian strength and the real spectrum appears in the ΓY direction. The PCs have been validated as the complex conjugate medium (CCM) by effective medium theory (EMT). Conversely, EMT indicates that the effective refractive index has a large imaginary part along the ΓX direction, which forms an evanescent wave inside the PCs. Consequently, coherent perfect absorption (CPA) and laser can be achieved in the directional emission of the ΓY. The outgoing wave in the ΓX direction is weak, which can significantly reduce the losses and electromagnetic interference. The non-Hermitian PCs enable many fascinating applications such as signal amplification, collimation, and angle sensors.

Realizing the topological rainbow based on cavity-coupled topological edge state

Topological photonic crystals (PCs) can support topologically protected states of light. These states are immune to backscattering and can be used to construct a variety of optical devices. One promising application of topological PCs is the formation of a topological rainbow. We propose a method for realizing a topological rainbow based on cavity-coupled topological edge state (TES) in a topological photonic crystal waveguide (TPCW). This is a new type of cavity coupled TPCW, in which the cavity is located inside the waveguide at the interface between two topologically distinct PCs. We demonstrated that by varying the cavity length in the TPCW, the separation of different frequencies of topological states can be controlled. Moreover, we showed that the topological rainbow is unaffected by the cavity shape inside the TPCW. This method is more robust and versatile than previous methods, as it is unaffected by the cavity shape. This makes it possible to create topological rainbow in a wide variety of high-performance devices. For example, it could be used to build topological rainbow in integrated circuits, which would be very difficult if the cavity shape was precisely controlled. We hope our findings will inspire further research in this area and lead to the development of new and innovative optical devices.

Electrically Tunable Topological Notch Filter for THz Integrated Photonics

AbstractElectromagnetic filtering is essential for emerging integrated photonic technologies and widely adaptable processing of high‐bandwidth signals. The conventional electro‐optic modulator‐based photonic approach for signal filtering at microwave frequencies cannot be implemented at terahertz (THz) frequencies due to the unavailability of the THz signal‐driven optical modulator. Here, an electrically tunable on‐chip THz photonic notch filter based on the topologically protected valley hall waveguide‐cavity platform is demonstrated. The device shows a significantly large notch suppression depth of more than 20 dB with a return loss of 13 dB in the entire tuning range of notch frequency. The feedback control circuit enables precise control of the notch frequency shift with a minimum step size of 7 MHz. This work extends the application of topological photonic crystals in developing THz‐integrated photonic devices for transformative technologies, including sixth‐generation (6G) communication and high‐resolution spectral sensing.

Research on applications of photonic crystals

A photonic crystal is a dielectric structure in which the refractive index varies periodically in space. Due to its special physical properties, it has theoretical research value and wide application prospects. This paper introduces photonic crystals from the aspects of principle, preparation and application, and makes a summary and outlook on them. This paper focuses on the basic principles and applications of photonic crystals, so as to help more people to have a general understanding of photonic crystals.

Bottom-up assembled photonic crystals for label-free sensing: Evaluation between photonic band gap and Fabry−Pérot fringes

The major challenge of the application of photonic crystals (PhCs) biosensors is the test sensitivity, selectivity, and reliability of the target analytes in complex real samples, like bodily fluids. Herein, we introduce the concept of utilizing the optical thickness (OT), which came from Fabry−Pérot fringes (F−P fringes), of bottom-up assembled PhCs to replace the traditional photonic band gap (PBG) as a parameter for biosensing process monitoring and quantification of analytes. The bottom-up assembled silica PhCs films are specialized to own a thickness with good interferometric properties and an ordered porous interconnecting and mechanically stable structure as a scaffold for biological reactions. By selecting a specific diameter (190 nm) of the silica PhCs building block, both PBG and F-P fringes can be observed on the spectrum simultaneously at the range of white light, and during detection, mutual interference between the two can be minimized to a great extent. This study finds that nearly 14 times lower low limit of detection (LLoD) can be achieved with F−P fringes than the PBG in ethanol concentration benchmark test on the same silica PhCs film. The thrombolysis experiment and human immunoglobulin G content evaluation in human plasma also show the sensitivity and reliability of F−P fringes in real samples, which PBG property can not perform well. This is the first systematic comparison study on PBG and F−P fringes in silica PhCs films.

Photonic Crystal Enhanced Fluorescence: A Review on Design Strategies and Applications.

Nanoscale fluorescence emitters are efficient for measuring biomolecular interactions, but their utility for applications requiring single-unit observations is constrained by the need for large numerical aperture objectives, fluorescence intermittency, and poor photon collection efficiency resulting from omnidirectional emission. Photonic crystal (PC) structures hold promise to address the aforementioned challenges in fluorescence enhancement. In this review, we provide a broad overview of PCs by explaining their structures, design strategies, fabrication techniques, and sensing principles. Furthermore, we discuss recent applications of PC-enhanced fluorescence-based biosensors incorporated with emerging technologies, including nucleic acids sensing, protein detection, and steroid monitoring. Finally, we discuss current challenges associated with PC-enhanced fluorescence and provide an outlook for fluorescence enhancement with photonic-plasmonics coupling and their promise for point-of-care biosensing as well monitoring analytes of biological and environmental relevance. The review presents the transdisciplinary applications of PCs in the broad arena of fluorescence spectroscopy with broad applications in photo-plasmonics, life science research, materials chemistry, cancer diagnostics, and internet of things.

Realization of a novel multimode waveguide with photonic band gap hopping based on coupled-resonator optical waveguide theory

Traditionally, in the application of photonic crystals, defect modes are mostly introduced in the photonic band gap to realize high-performance waveguides, and electromagnetic waves beyond the photonic band gap cannot be controlled in photonic crystals. Here we demonstrated a kind of deep subwavelength quasi-photonic crystal waveguide, named 2D closed surface-wave photonic crystal, by combining a photonic crystal with a spoof surface plasmon polaritons-based metal–insulator–metal structure. The closed surface-wave photonic crystal waveguide can realize the introduction of the defect mode in the frequency band where the first-order dispersion curve of the surface-wave photonic crystals is located, instead of being limited to the frequency range of the photonic band gap of surface-wave photonic crystals. At the same time, we confirmed the correctness of the coupled-resonator optical waveguide theory under the conditions of the first-order mode and the multi-order mode based on the closed surface-wave photonic crystal guided-wave mechanism. We have verified our work in 80–130 GHz through experiments, theory, and simulation, which are consistent. The closed surface-wave photonic crystals can be used as a kind of highly integrated waveguide and multi-bandpass/band-elimination filter in integrated optical circuits, and can adjust the working frequency band at very low cost.

Photonic Crystal Circuitry and its Impact on Wireless Networks

Wireless networks are considered a hot topic in dealing with data without need to routers or other infrastructures. Each node has a part of routing responsibility. This result to a huge of data in forwarding to other nodes and will need high speed to process. Photonic crystal applications come to solve the necessity for such speed with small circuitry area. One of the main factors that affect their operation is the structure topology. Ring resonator, cavity based structures, self-collimation, and waveguide approaches are some of these topologies. OR gate is proposed in this paper to be simulated and evaluated as one of the basic element block. This design is built on a square lattice- photonic crystal construction on a ring resonator basis. Rotation of 90, 180, and 270 degrees are applied in clockwise direction. Sensitivity analysis, and carefully rod locations are considered to obtain remarkable performance. Minimum size and highly data rate are two characteristics that discriminates this design. The minimum size of 51.48 μm2 is obtained. The bit rates of 1.35, 6.35, 3.2, and 2.53 Tbs are calculated with the 0, 90, 180, and 270 degrees, respectively. Comparison table is well organized for the recently published photonic crystal OR-gate that based on ring resonator. Finite difference time domain and Plan wave expansion method are used to analyze the proposed structure at 1.55μm wavelength to verify OR- gate operation.

СТРАТЕГІЇ ТЕХНОЛОГІЧНОГО РОЗВИТКУ АПАРАТНОГО ЗАБЕЗПЕЧЕННЯ ІНФОКОМУНІКАЦІЙНИХ РАДІОМЕРЕЖ

Technologies for building telecommunication systems and networks based on 6G technology, which will be able to provide access to new functionality and information services using innovative wireless technologies and artificial intelligence methods, are considered. At the same time, information communication systems based on 6G are characterized by new functional parameters and devices, in particular, a new spectrum, new channels, new materials, new antennas, new computing technologies and new end devices, taking into account the possibility of simultaneous use of the THz range for communication and the scanning process. The operation of communication and scanning systems in new high-frequency ranges based on new materials and antennas is based on the application of silicon photonics, photonic crystals, heterogeneous, reconfigurable, photoelectric and plasmonic materials. At the same time, there is also a need to use new types of antennas for the THz frequency ranges. This is especially important, because due to significant transmission losses in the THz range, antennas are significantly different from conventional antennas that are connected to radio frequency systems via coaxial cables or microstrip lines. Given that Moore's law will soon lose its relevance, research into new computing technologies, such as computing based on artificial intelligence structures and quantum computing, has begun. The key indicators of the effectiveness of future telecommunication terminal devices as part of 6G information communication radio networks are considered and their functional capabilities are determined. The study of the architecture of terahertz communication systems was carried out using two different approaches to the construction of hardware: electronic, where radio frequencies are multiplied up to THz; and photonic, where optical frequencies are divided up to THz. It has been determined that most of such systems and networks are used for communication over short distances inside premises due to high atmospheric attenuation in the THz range. The prerequisites for achieving higher characteristics due to the addition of new materials to the silicon chip, such as photonic crystals, photovoltaic elements and plasma surfaces, are considered. As a result, new on-chip and in-body antenna designs, along with compact lens technology such as RIS, can provide more accurate implementation of the desired antenna characteristics, as well as reduce system size. Opportunities to use new communication and visualization methods have been identified, but implementation of terahertz systems based on electronics, optoelectronics, and photonics will depend on the usage scenario and operating frequencies.

Fabrication techniques and applications of two-dimensional photonic crystal: history and the present status

The idea of photonic crystal came to be when E. Yablonovitch and S. John recommended a structure in 1987 having periodic alteration of refractive index in one or multiple directions. Photonic crystals have the potential to manipulate and tailor the flow of light across the crystal, which gives advantage to invent many photonic devices on the microscopic scale having very small footprints. In recent years several articles have been published on the advances of photonic crystal-based structures. This review article mainly focuses on the several fabrication techniques of photonic crystals and their applications in different fields. Several photonic crystal-based structures such as logic gates, optical sensors, polarization beam splitters, and absorbers for solar cells are reviewed in this paper to show recent advancements on this trending topic. Also, a brief review of the different steps of fabrication of photonic crystals and different fabrication methods proposed by researchers is articulated in this paper.

Large-scale structural color on transparent plexiglass by nanosphere lithography combined with reactive-ion etching

Structural color due to unique optical response are of much interest both for their fundamental properties and applications in photonic integrate circuits, optical biomaterials and camouflage. Nanosphere lithography combined with reactive-ion etching demonstrates a feasible strategy to achieve large-scale photonic crystals with structural color. In this work, polymethyl methacrylate (PMMA), namely plexiglass, was firstly used as photonic crystals substrate to fabricate large-area and novel nanopillar arrays via reactive-ion etching monolayer polystyrene (PS) sphere arrays. The height and diameter of plexiglass’ nanopillars can be controlled by adjusting PS size and etching time. In addition, PS sphere arrays exhibited charming structures like chrysanthemum after O2 plasma etching with higher intensity. The nanopillar arrays exhibited the tuned band-gap of such structures with different sizes and tunable resonance peaks from 350 nm to 600 nm. The fabricated nanopillar arrays have potential applications in solar cells, self-cleaning materials, photonic crystals and nonlinear optics.