Crystal Resonator Research Articles

Cyano‐Substituted Distyrylbenzene Derivative for Laser Media: High Solid‐State Luminescence and Processabilities by Tert‐Butyl Appending Design

AbstractTo create effective organic laser media, it is essential to design molecules with high photoluminescence (PL) quantum efficiency (ΦPL), solubility‐processability for facile crystal resonator formation, and structural tunability. Cyano‐β‐substituted distyrylbenzene (CDSB) is recognized as a potential solid‐luminogen but is limited by its quantum efficiency and solubility toward crystal resonator processability. Herein the rational design for high solid‐state luminescence and processability is demonstrated through designing tertiary‐butyl (tBu)‐appended approach. In contrast, tBu‐appended CDSB, namely tBuC, has good solubility for crystal growth processability and controllability, allowing for the formation of high ΦPL polymorphs. tBuC offers selective growth for (I) green‐emissive platelet crystals or (II) blue‐emissive needle crystals. The ΦPL is 0.72 for I and 0.91 for II. The ΦPL value for II is among the highest in the CDSB series, attributed to the segregated luminescent species based on bulky tBu. Lasing is observed for II due to the above characteristics. The addition of tBu offers a new strategy for crystal engineering toward the realization of laser media although it is a chemically simple approach.

Advanced photonic crystal fiber-based surface plasmon resonance biosensors for transformative RI sensing

Advanced photonic crystal fiber-based surface plasmon resonance biosensors for transformative RI sensing

A Multi-Functional VOC Sensor Based on Cascaded Quartz Crystal Resonators

A Multi-Functional VOC Sensor Based on Cascaded Quartz Crystal Resonators

Performance Analysis of Chirped Graded Photonic Crystal Resonator for Biosensing Applications

Performance Analysis of Chirped Graded Photonic Crystal Resonator for Biosensing Applications

Determination of Lactoferrin Using High-Frequency Piezoelectric Quartz Aptamer Biosensor Based on Molecular Bond Rupture.

In this study, an aptamer biosensor for detecting lactoferrin (LF) was developed using piezoelectric quartz-induced bond rupture sensing technology. The thiol-modified aptamer I was immobilized on the gold electrode surface of the quartz crystal microbalance (QCM) through an Au-S bond to specifically bind LF. It was then combined with aptamer-magnetic beads to amplify the mass signal. The peak excitation voltage was 8 V at the resonance frequency for the 60 MHz gold-plated quartz crystal. When the molecular bond cracking process occurred, the aptamer-magnetic beads combined on the surface of the piezoelectric quartz were removed, which resulted in an increase in quartz crystal resonance frequency. Therefore, the specific detection of LF can be realized. Under optimized experimental conditions, the linear range for LF was 10-500 ng/mL, the detection limit (3σ) was 8.2 ng/mL, and the sample recoveries for actual milk powder samples ranged from 97.2% to 106.0%. Compared with conventional QCM sensing technology, the signal acquisition process of this sensing method is simple, fast, and easy to operate.

Characterizing X-Ray and Solution State Conformations for a Model Qubit System: {Cr7Ni} Ring Rotaxanes on a Mixed Metal Triangle.

The synthesis of a series of [4]rotaxanes, each consisting of three [2]rotaxanes joined via a central {CrNi2} triangular linker, is reported. The resultant four [4]rotaxanes were characterized by single crystal X-ray diffraction and electron paramagnetic resonance (EPR) spectroscopy. Orientation-selective 4-pulse double electron-electron resonance (DEER) measurements between the three {Cr7Ni} rings incorporated in each [4]rotaxane reveal that each system is conformationally fluxional in solution, with the most abundant conformations found to differ significantly from the crystal structure geometry for each compound. The degree of similarity between conformations is evaluated using a novel application of the earth mover's distance analysis.

Retraction Note: design and simulate the demultiplexer using photonic crystal ring resonator for DWDM system

Retraction Note: design and simulate the demultiplexer using photonic crystal ring resonator for DWDM system

Design and Characteristics of Photonic Crystal Resonators for Surface-Emitting Quantum Cascade Lasers

We present our recent development of the surface-emitting quantum cascade laser with a PC (photonic crystal) resonator and a strain-compensated MQW (multiple quantum well) active layer operating at around 4.3 μm. We describe the laser performance mainly from the viewpoint of the design and analysis of the PC resonators, which include both numerical calculations by FEM (finite element method) and analytical calculations using the k·p perturbation theory and group theory. We analyze the resonance quality factor, overlap factor, extraction efficiency, and far-field pattern, and show how the output power and beam quality have been improved by the appropriate design of the PC resonator.

Dielectric Surface-Based Biosensors for Enhanced Detection of Biomolecular Interactions: Advances and Applications.

Surface plasmon resonance (SPR) biosensors are extensively utilized for analyzing molecular interactions due to their high sensitivity and label-free detection capabilities. Recent innovations in surface-sensitive biosensors with dielectric surfaces address the inherent limitations associated with traditional gold surfaces, such as thermal effects and biocompatibility issues, which can impede broader applications. This review examines state-of-the-art biosensor configurations, including total internal reflection, optical waveguide, photonic crystal resonators, Bloch surface wave biosensors, and surface electrochemical biosensors, which can enhance analyte signals and augment the molecular detection efficiency at the sensor interface. These technological advancements not only improve the resolution of binding kinetics analysis and single-molecule detection but also extend the analytical capabilities of these systems. Additionally, this review explores prospective advancements in augmenting field enhancement and incorporating multimodal sensing functionalities, emphasizing the significant potential of these sophisticated biosensing technologies to profoundly enhance our understanding of molecular interactions.

Generation principle for robust and regularly spaced resonant modes in a nontopological photonic crystal ring resonator

Generation principle for robust and regularly spaced resonant modes in a nontopological photonic crystal ring resonator

All-optical simultaneous OR and AND optical logic gates based on nonlinear photonic crystal ring resonator

Abstract An all-optical simultaneous OR and AND logic gates using the nonlinear Kerr effect and ring resonator based on a two-dimensional photonic crystal are proposed in this paper. The proposed structure has a resonant wavelength of 1551.3 nm and a power consumption (1 kW/μm2). The proposed structure is suitable for all-optical photonic integrations because of its simplicity and small size (23 μm x 30.4 μm). Moreover, the structure executes two logic operations without requiring an additional spare/control signal through a single structure, making fabrication easy. The total footprint of the photonic crystal ring resonator structure measures approximately 699 μm². A very high contrast ratio of 26.10 dB and 25.34 dB is obtained for the OR and AND logic gates, with response times equal to 2 ps and 0.67 ps, respectively. In addition, the calculated bit rates for OR and AND logic gates are approximately 0.5 and 1.5 Tbps, respectively. Using the Rsoft CAD commercial software, the FullWAVE and BandSOLVE module of the software is used for numerical and theoretical investigation of the structure.

Design optimization of phononic-fluidic resonator systems

Phononic-fluidic resonators utilize an acoustic fluid domain as a defect inside a solid metamaterial lattice, which can be used used to precisely measure acoustic properties of liquids. The design goal is to offer ideal boundary conditions for the acoustic resonator by matching defect resonance with phononic band gap. The design space of metamaterial or phononic crystal and fluidic resonator is nearly unlimited, especially when utilizing fully three-dimensional structures. In this work, we explore numerical shape and topology optimization to focus acoustic energy into the fluid domain and maximize the quality factor of the defect resonance. This requires the use of complex multi-frequency objective functions, while taking into account practical limits such as finite size and losses in the fluid and solid domains. Results highlight notable but limited improvements of quality factor with shape optimization starting from an initial design constrained by the maximum deformation possible. On the other hand, topology optimization results offer unique and unexpected ideas, and thus a deeper dive into the design space.

Design and simulation of 1×3 acoustic demultiplexer based on hexagonal phononic crystal ring resonators

Design and simulation of 1×3 acoustic demultiplexer based on hexagonal phononic crystal ring resonators

Highly Doped Single Crystal Al₁-ₓScₓN Bulk Acoustic Resonators for High-Frequency and Wideband Applications

Highly Doped Single Crystal Al₁-ₓScₓN Bulk Acoustic Resonators for High-Frequency and Wideband Applications

Enhanced four-band absorption in a tunable graphene subwavelength grating structure for photodetection

This paper investigates a sub-wavelength multilayer dielectric grating structure based on a simple metasurface, achieving dynamically switchable four-band absorption enhancement. This enhancement spans the visible to near-infrared (NIR) range, with absorption exceeding 90%, representing nearly a 40-fold increase over the intrinsic absorption of a single graphene layer. The contributions of guided-mode resonance (GMR), optical Tamm state (OTS), and photonic crystal defect cavity resonance to the absorption spectra are analyzed separately, offering a method for independent multi-channel signal extraction. Additionally, we explore the impact of structural parameters on the absorption response and examine the broad-spectrum multiband detection mechanism. This mechanism, explained through the integration of resonant cavity perturbation theory and the dynamic tuning of absorption efficiency via graphene's Fermi energy levels, results in an independently tunable optical system for four key operating bands. These properties make the structure suitable for applications such as multiband biomedical photodetectors or components in optoelectronic devices with multiple operating bands.

Practical limits of the quartz crystal microbalance and surface plasmon resonance for elucidating salt or ion partitioning into membrane polymers

Determining the partitioning of sodium chloride into polyamide (PA) reverse osmosis membranes used for seawater desalination is indispensable for optimizing the salt retention of the membranes. Furthermore, the recent quest for ion-selective membranes requires physico-chemical characterization techniques capable of elucidating partitioning phenomena of ions into membrane polymers in general. Quartz-crystal microbalance with dissipation monitoring (QCM-D) has been explored for this purpose as it has in theory a sensitivity in the range of pg/cm2 and is an accessible and apparently simple method to use. However, it is a technique that intrinsically lacks an internal reference, and it is affected by liquid bulk changes. As the conventional applications of QCM-D are of biophysical nature where changes in solute concentrations are in the nano to micromolar range, we investigated systematically in how far QCM-D yields reliable results for determining salt partitioning coefficients at concentrations relevant for the industrial-scale. We could clearly demonstrate that QCM-D possibly detects salt absorption only at salt concentrations higher than that in seawater (0.6 M). Furthermore, the variation in the liquid bulk response was so significant that it overlapped with a possibly perceived response due to salt absorption. Therefore, we concluded that salt partitioning coefficients derived from QCM-D data have a low confidence and, in any case, should always be reported accompanied by the raw data. We corroborated these findings with multi-parameter surface plasmon resonance (MP-SPR) which widely confirmed the trends observed with QCM-D.

Double-formant PCF-SPR refractive index sensor with ultra-high double-peak-shift sensitivity and a wide detection range.

A dual-resonance-peak photonic crystal fiber-surface plasmon resonance (PCF-SPR) refractive index (RI) sensor is designed for different wavelength ranges. The first resonance peak of the sensor is distributed in the wavelength range of 700-2350nm, while the second peak is distributed in the range of 2350-5550nm. In addition to detecting analytes using the full spectrum of constraint losses (CLs), it is also possible to use a single resonance peak to achieve the detection of analytes. By systematically optimizing the nanowire diameter, the diameter of the inner and outer layer air hole, the width of the groove, the polishing depth, and the distance from the outer layer air hole to the fiber core, the optimal structure of the sensor is finally determined. In this study, the sensor was studied by numerical analysis, and the characteristics of the sensor were evaluated by wavelength detection technology. The results show that within the RI range of 1.24-1.37, the sensor has a maximum wavelength sensitivity (WS) of 54700nm/RIU for detecting the RI of analytes. Within the above refractive index range, the regression coefficient R 2 of the dual-peak-resonance wavelength is 0.99993, ensuring the accuracy of the estimated resonance wavelength of the sensor. In addition, the sensor can also use dual-peak-shift sensitivity (DPSS) to detect the refractive index, which is a relatively new sensing technology. The maximum DPSS of the sensor is 95300nm/RIU. Due to its high sensitivity and unique dual-peak characteristics, this sensor has wide application prospects in medical diagnosis, environmental monitoring, food safety, and other fields.

Photonic defect modes in cholesteric liquid crystal resonators with embedded isotropic layers

Photonic defect modes are explored as a viable alternative to standard photonic band edge modes in photonic crystal applications, especially due to their typically high Q-factors and local density of states. For example, they can be used in nonlinearity enhancement, lasing, and cavity quantum electrodynamics. However, they are strongly dependent on any structural change and need to be well-controlled to ensure the desired resonance frequency. Here, we present a study of the photonic defect modes that appear in a structure where a layer of isotropic material is embedded between two layers of cholesteric liquid crystal (CLC), using full electrodynamics numerical simulations. We present typical transmission spectra and electric field profiles of selected defect modes and then analyze the influence of geometrical and material parameters on the eigenfrequencies and Q-factors of the modes within and around the photonic bandgap, including refractive indices and thicknesses of isotropic and liquid crystal layers, and different anchoring orientations at the boundaries of the isotropic defect layer. Additionally, a connection of such defect modes to previously extensively analyzed twist defect modes is given. Eigenmodes in asymmetric resonators are also presented, where CLC layers surrounding the intermediate isotropic layer are not equally thick, enabling biasing of specific directional light emission. More generally, this work aims to contribute to the understanding and design capability in topological soft matter photonics where defect mode lasing could be realized in CLC geometries with different singular and solitonic topological defect structures.

Retraction Note: Demultiplexer design using photonic crystal ring resonator with high quality factor and less footprint for DWDM application

Retraction Note: Demultiplexer design using photonic crystal ring resonator with high quality factor and less footprint for DWDM application

Design and simulation of an enhanced optical demultiplexer using photonic crystal resonators

The purpose of this paper is to examine the design, simulation, and optimization of a demultiplexer optical system using photonic crystal resonators. Utilizing the distinct properties of photonic crystals, the proposed device achieves high-quality resonances, efficient wavelength separation, and minimal crosstalk. These characteristics are crucial for enhancing the performance of dense wavelength division multiplexing (DWDM) systems, which require precise and efficient channel separation to manage increasing data traffic. Extensive simulations conducted with the RSoft CAD tool explore the impact of varying resonator parameters such as refractive index, geometric dimensions, and material composition on the device's performance. The results indicate substantial improvements in transmission efficiency and quality factor, with average values of 98.675% and 3131.125, respectively. Furthermore, the ability to fine-tune these parameters allows for the customization of the demultiplexer to specific wavelength ranges, making it highly adaptable for various telecommunications applications. This research aims to propel the development of compact, high-performance photonic devices that meet the growing demands of modern communication networks, ultimately contributing to more efficient and reliable optical communication systems.