Cavity System Research Articles

Generation and enhancement of sum sideband in a magnon Kerr nonlinearity assisted optomechanical system

Abstract A theoretical scheme to enhance the sum sideband generation (SSG) via magnon Kerr nonlinearity assisted optomechanical system is proposed. In this scheme, the yttrium iron garnet sphere is placed within the cavity system and the frequency components are generated at the sum sideband through optomechanical nonlinear interaction and cavity-magnon linear coupling interaction. The results show that the efficiency of SSG can be enhanced by several orders of magnitude, and the gain in SSG efficiency also varies. The dependence of SSG on the system parameters, including the power of the control field, the frequency detuning of the probe fields and the coupling strengths between the optomechanical coupling and the cavity-magnon coupling is analyzed in detail. The change of SSG by varying the optomechanical coupling strength and cavity-magnon coupling strength is also investigated, and it is found that new matching conditions are generated. The enhanced SSG method may have potential application prospects in realizing the measurement of high-precision weak forces, quantum information processing and quantum-sensitive sensing.

Quantum effect in a hybrid bose-einstein condensate opto-magnomechanical system

Abstract We present a hybrid opto-magno-mechanical cavity system consisting of an optical cavity that creates an opto-mechanical cavity with a fixed mirror, a magnon mode in a ferrimagnetic crystal linked to the movable mirror and an intracavity Bose–Einstein condensate. The mechanical displacement is coupled to the magnon by the magnetostriction force and to the optical cavity by the radiation pressure, and the latter is also weakly coupled to a Bose–Einstein condensate. We provide a strategy to measure and quantify entanglement using logarithmic negativity. In addition, we study the quantum or EPR steering in order to present the stationary quantum steering. We consider that all composite modes in our model are given in a Gaussian state described by a covariance matrix. In these studies, we focus on the interaction between the Bose–Einstein condensate and the magnonic modes in a ferrimagnetic crystal. It is important to note that we use experimentally controllable realizable parameters to observe the interaction of modes at temperatures in the microkelvin range.

Quantization of optical quasinormal modes for spatially separated cavity systems with finite retardation

Quantization of optical quasinormal modes for spatially separated cavity systems with finite retardation

Biomarkers of renal parenhimal damage in young children with congenital hydronephrosis (literature review).

Enlargement of the fetal renal cavity system occurs in 1-5% of cases during prenatal ultrasound examination and can be caused by congenital hydronephrosis as having pelvi-ureteric junction obstruction, which is one of the most common nosologies in the structure of obstructive uropathy in childhood. The high risk of decreased renal function at the preclinical stage of disease development dictates the need to create highly informative diagnostic programs and treatment algorithms aimed at preventing the development of complications. In this review, we discuss the results of studies on the diagnostic and prognostic value of cytokine biomarkers that are of greatest interest in congenital hydronephrosis in young children, these include: KIM-1, VEGF-A, MCP-1, NGAL, IL-1. The literature search for writing this review was carried out using the Web of Science, PubMed, RSCI, CyberLeninka, Scopus databases.

Reciprocal or nonreciprocal bimolecular interface and quantum entanglement

We study a hybrid system of a plasmonic cavity coupled to a pair of different molecular vibration modes with the strong optomechanical-like interactions. Here, this plasmonic cavity is considered as a quantum data bus and then assist several applications. For instance, it can first establish a bimolecular interface to ensure the reciprocal or non-reciprocal information transmission, and then engineer both molecules into the steady-state quantum entanglement of the continuous variable through the dissipative method. In contrast to the traditional optomechanical system, this hybrid system can provide the stronger optomechanical-like interactions and more convenient controls to the molecular quantum units. This investigation is believed to be able to further expand the practical application range of quantum technology.

Three-cavity system with multiple magnomechanically induced transparency

This paper presents the characteristics of a weak probe field in a three-connected cavity system. In this system, a microwave cavity contains a yittrium iron garnet sphere that is driven by a strong pump and a weak probe optical fields, and the magnon is driven by a weak microwave source. The other two cavities are empty and are coupled to the first cavity with specific coupling strengths. This setup leads to the observation of multiple magnomechanically induced transparency phenomena by varying quantum parameters g ma, g mb, and the coupling strengths between cavities J 1 and J 2. The study of these phenomena in the three coupled cavities can potentially contribute to advancements in quantum transduction and future technologies.

Pressure control of tritiated hydrogen isotopologues in hermetically sealed vessels by non-evaporable getters for sub-Doppler-resolution spectroscopy

Small molecules serve as valuable benchmarks for testing quantum chemical theories. Ultra-high-resolution spectroscopy currently offers the capability of measuring molecular hydrogen energy levels with a relative accuracy on the order of 10-10. Expanding such investigations to encompass different isotopologues of molecular hydrogen has emerged as a promising avenue for examining mass-dependent contributions to the full description of molecular structure in the framework of relativistic quantum electrodynamics. However, the delicate nature of handling radioactive tritium in a high-resolution spectroscopy environment poses significant technological challenges, thereby limiting the extension of these studies to include T2, DT and HT isotopologues. In this work, we present the experimental setup of the very sensitive, Doppler-free technique of Noise-Immune Cavity-Enhanced Optical Heterodyne Molecular Spectroscopy (NICE-OHMS), used to measure rovibrational transitions in the HT molecule. The NICE-OHMS measurements were performed in a closed cavity system without connection to an actively pumped vacuum system. For this reason, a new method for tritium storage and pressure regulation within 0.05–1Pa based on a temperature-controlled mini-getter system is employed using less activity than the tritium exemption limit (1GBq). Non-Evaporable Getters of the type SAES St171 were used for this purpose exploiting their property that hydrogen is released upon heating, while other gases remain being pumped. Prior to the NICE-OHMS experiment, the reversible sorption properties of the getter for hydrogen isotopes were investigated. We show measurements of the equilibrium (hydrogen) pressure for all three pure isotopes and for a H2:HT:T2 mixture (with H:T = 1:1) as a function of temperature for a system of defined volume and amount of gas. For the read-out of the temperature, a method using the resistance of the getter in combination with a pyrometric calibration has been implemented. We discuss the experiences from practical use of the tritium getter and show results obtained with the NICE-OHMS setup leading to frequency calibration of near-infrared transitions in HT at an accuracy, surpassing previous studies by nearly three orders of magnitude.

A multiphysics simulator for stope-coupled heat exchanger operation in deep underground mines

The ever-increasing mine depth offers unprecedented opportunities to access high-grade geothermal resources. By pre-installing pipeline systems in mined-out cavities before waste tailings placement, the stope-coupled heat exchanger (SCHE) has drawn growing attention for its superior socio-economic advantages. However, despite the extensive focus on energy efficiency, the system stability during heat production has been typically overlooked. This study therefore introduces a novel high-fidelity simulator for replicating practical SCHE operation. By embedding non-isothermal pipe flow into an evolutive thermo-poromechanics framework for cemented tailings, the outlet water temperature and multiphysics backfill response in diverse production settings are meticulously studied. Our calculations reveal for the first time that circulating chill fluid within mine backfill can substantially alleviate pressure development, suggesting enhanced system stability with heat-exchanger implementation. We also demonstrate that albeit targeting higher-grade geothermal resources, prioritizing cold-season operation, and pre-charging heat exchangers with production delays could spur heat productivity, the companion thermal pressure generation might still impose significant overloading risks. Conversely, while fast circulation would diminish the end-utilization temperature, the rapid heat removal could indeed facilitate superior efficiency and stability performance for the geothermal system. We believe these new findings hold critical implications for better positioning SCHE as a safely sustainable pathway towards hybrid utilization of deep resources.

Multi-Objective Optimization of the Pre-Swirl System in a Twin-Web Turbine Disc Cavity

Enhancing thermal efficiency and minimizing weight are prevailing issues in aero engines. Owing to its hollow structure, the twin-web turbine disc exhibits remarkable weight reduction properties, while its enhanced cooling constitutes a novel challenge. In this study, a twin-web turbine disc cavity system is numerically investigated. To enhance the cooling effect and minimize pressure loss, a multi-objective genetic algorithm and Kriging surrogate model are employed to optimize the radial height of the pre-swirl nozzle and receiver hole in the disc cavity system. The results indicate that the overall performance of Opt-3, derived from the Technique for Order Preference by Similarity to the Ideal Solution method within the Pareto frontier, is superior. This configuration achieves a uniform low distribution of rotor temperatures while maintaining moderate pressure losses. Notably, the maximum temperature is reduced by 21.1 K compared to the basic model, with pressure losses remaining largely unchanged. Additionally, an increase in the flow ratio leads to a reduction in both the maximum temperature and average temperature of the back web while simultaneously increasing the temperature of the front web and augmenting pressure losses. However, it is important to note that the degree of variation in these parameters diminishes with increasing flow ratios.

Experimental demonstration of frequency- downconverted arm-length stabilization for a future upgraded gravitational wave detector.

Ground-based laser interferometric gravitational wave detectors (GWDs) consist of multiple optical cavity systems whose lengths need to be interferometrically controlled. An arm-length stabilization (ALS) system has played an important role in bringing these interferometers into an operational state and enhancing their duty cycle. The sensitivity of these detectors can be improved if the thermal noise of their test mass mirror coatings is reduced. Crystalline AlGaAs coatings are a promising candidate for this. However, the current ALS system with a frequency-doubled 532 nm light is no longer an option with AlGaAs coatings because the 532 nm light is absorbed by AlGaAs coatings due to the narrow bandgap of GaAs. Therefore, alternative locking schemes must be developed. In this Letter, we describe an experimental demonstration of a novel ALS scheme, to the best of our knowledge, which is compatible with AlGaAs coatings. This ALS scheme will enable the use of AlGaAs coatings in current and future terrestrial gravitational wave detectors.

Impregnation problems of aluminum castings

Abstract Vacuum impregnation is an effective solution to the porosity problem of aluminum die castings. Experience has shown that quality die-cast aluminum alloy products manufactured with gas tightness requirements can show leakage even after impregnation operation. The study seeks to answer the question of the geometry of the cavity system through which leakage occurs and why the cavity system is not saturated with liquid resin during impregnation. It is assumed that insufficient impregnation occurs if the near-surface parts of the cavity system are heavily deformed locally during the machining of the casting.

Adolescent smoking as risk factor of decrease in adaptation resources of neutrophil metabolism in oral cavity and progressive recurrent bronchitis

High prevalence of smoking among children and its early onset is an urgent problem in modern pediatrics. For proper health risk quantification, it is extremely important to understand and parameterize relationships between effects of adverse factors and physiological processes in the body, including the cellular level. The aim of this study was to analyze how tobacco smoking influences maladaptive changes in the mucosal immunity system of the oral cavity in adolescents and to assess kinetic trends in the clinical course of recurrent bronchitis (RB) in long-term outlook. The study included 92 patients with RB aged 16.8 ± 3.1 years. Two groups were created of them; the observation group was made of 64 patients, who admitted smoking as a habit, and the reference group included 28 people without nicotine addiction. The control group was made of 23 adolescents of the same age without any signs of the analyzed disease. Oral neutrophils (N) were selected as basic research material. N oxygen metabolism was registered by luminol-dependent chemiluminescence (LDCL) in spontaneous (sLDCL) and induced (iLDCL) variants. Functional N probing was performed using opsonized zymosan (Σ) and and peptidoglycan from S. aureus strain Cowan. Concentrations of antibodies (AT) to glycolipid (GLP) (Re-mutant Salmonella Minnesota), Candida albicans and S. аureus were determined by ELISA tests. The analyses made it possible to detect a close relationship between levels of ROS generation by neutrophilic granulocytes and the immune components of anti-endotoxic immunity. Immune changes were not established to be universal in the groups of examined patients and were shown to reflect the specificity of destabilizing effects produced by tobacco smoke. A direct moderate correlation was established in the observation group between sLDCL indicators and the concentration of anti-candidosis antibodies (r = +0.59, p = 0.0382), which reflects the level of bacterial stimulation involving dysbiotic shifts in gut microbiota. A direct correlation was detected between levels of biocidal parameters of neutorphil granulocytes and anti-glycolipid levels (r = +0.64 p = 0.417).

Курение подростков как фактор риска снижения адаптационных ресурсов метаболизма нейтрофилов ротовой полости и прогрессирующего течения рецидивирующего бронхита

High prevalence of smoking among children and its early onset is an urgent problem in modern pediatrics. For proper health risk quantification, it is extremely important to understand and parameterize relationships between effects of adverse factors and physiological processes in the body, including the cellular level. The aim of this study was to analyze how tobacco smoking influences maladaptive changes in the mucosal immunity system of the oral cavity in adolescents and to assess kinetic trends in the clinical course of recurrent bronchitis (RB) in long-term outlook. The study included 92 patients with RB aged 16.8 ± 3.1 years. Two groups were created of them; the observation group was made of 64 patients, who admitted smoking as a habit, and the reference group included 28 people without nicotine addiction. The control group was made of 23 adolescents of the same age without any signs of the analyzed disease. Oral neutrophils (N) were selected as basic research material. N oxygen metabolism was registered by luminol-dependent chemiluminescence (LDCL) in spontaneous (sLDCL) and induced (iLDCL) variants. Functional N probing was performed using opsonized zymosan (Σ) and and peptidoglycan from S. aureus strain Cowan. Concentrations of antibodies (AT) to glycolipid (GLP) (Re-mutant Salmonella Minnesota), Candida albicans and S. аureus were determined by ELISA tests. The analyses made it possible to detect a close relationship between levels of ROS generation by neutrophilic granulocytes and the immune components of anti-endotoxic immunity. Immune changes were not established to be universal in the groups of examined patients and were shown to reflect the specificity of destabilizing effects produced by tobacco smoke. A direct moderate correlation was established in the observation group between sLDCL indicators and the concentration of anti-candidosis antibodies (r = +0.59, p = 0.0382), which reflects the level of bacterial stimulation involving dysbiotic shifts in gut microbiota. A direct correlation was detected between levels of biocidal parameters of neutorphil granulocytes and anti-glycolipid levels (r = +0.64 p = 0.417). Integral assessment of specific humoral immunity to glycolipid and the phagocytic link of the mucosal protection in the oral cavity reflects the degree of endogenous intoxication and kinetic trends in the RB clinical course in adolescents in subsequent years of life. These relationships may provide solid rounds for ‘exposure – response’ stage in the risk assessment procedure for assessing risks of respiratory diseases in smoking adolescents.

Generation of second-order sidebands and slow–fast light in cavity magnomechanics with a parametric amplifier

In this work, we theoretically investigate the optical second-order sideband (OSS) efficiency and group delay of an output probe field in a two-coupled cavity magnomechanics (CMM) system. The setup comprises a gain (active) cavity and a passive (loss) cavity, which simultaneously includes an optical parametric amplifier (OPA) and a yttrium iron garnet sphere to facilitate magnon–photon coupling. Employing experimentally attainable parameters, we show that the presence of an OPA can significantly enhance the optical transmission rate and OSS efficiency. We show that photon–magnon strong coupling can enhance OSS efficiency substantially when compared to weak photon–magnon coupling. Our results, in particular, show that the OSS’s efficiency may be significantly improved for active–passive-coupled cavities as compared to the passive–passive cavities system. Furthermore, we demonstrate that modifying the system configurations may change the group delay, affecting the transition from rapid to slow light propagation, and vice versa. Our results provide a novel and easy approach to designing CMM devices for altering light propagation, with possible applications including optical switching, information storage, and accurate measurement of weak signals.

A fast vibro-acoustic modeling method of plate-open cavity coupled systems

In this paper, a fast Chebyshev-Ritz method for vibro-acoustic analytical modeling of plate-open cavity coupled systems is developed for the first time. Based on the Chebyshev spectral method and the Rayleigh-Ritz solution procedure, the vibro-acoustic model of the open cavity coupled with a rectangular plate is established. The exterior acoustic field of the open cavity is expressed by the Rayleigh integral. Additionally, the Rayleigh integral is divided into a frequency-independent singular integral and a frequency-dependent non-singular integral, accelerating the calculation process. Furthermore, the Gauss-Chebyshev-Lobato sampling method is first developed for the plate-open cavity coupling model. By converting the integrals into tensor products, the method avoids complex quadruple integrals, increasing the efficiency of the entire integral operation. The vibration and acoustic responses from the proposed method agree well with existing literature and FEM analysis results, demonstrating the convergence and correctness of the current methodology. The mechanism of cavity depth on vibro-acoustic features of plate-open cavity systems is studied, which is less focused in the published literature. Other factors governing the plate-open cavity coupled model encompassed boundary conditions, fluid mediums, and plate thickness are fully examined. The results provide a theoretical foundation for the design and future research of plate-open cavity structures.

The effect of Casimir force on a diffraction grating in an optomechanical system

This study revisits an optomechanical cavity system to investigate how the Casimir force affects the manipulation of a diffraction grating. The proposed model consists of two mirrors, one of which is fixed while the other vibrates, and an external plate is used to generate the Casimir effect through the vibrating mirror. The Casimir effect has the potential to modify the properties of the output probe field (OPF), resulting in the phenomenon known as optomechanically induced transparency (OMIT), as reported in a previous study (Sci. Rep. 6, 27 102 (2016)). Interestingly, we observed that, when the Casimir effect exist, the maximum energy is transported to higher order. This theoretical realization of the diffraction grating could be feasibly tested in a physical experiment.

Analytical Methodologies to Detect N-Nitrosamine Impurities in Active Pharmaceutical Ingredients, Drug Products and Other Matrices.

Since 2018, N-nitrosamine impurities have become a widespread concern in the global regulatory landscape of pharmaceutical products. This concern arises due to their potential for contamination, toxicity, carcinogenicity, and mutagenicity and their presence in many active pharmaceutical ingredients, drug products, and other matrices. N-Nitrosamine impurities in humans can lead to severe chemical toxicity effects. These include carcinogenic effects, metabolic disruptions, reproductive harm, liver diseases, obesity, DNA damage, cell death, chromosomal alterations, birth defects, and pregnancy loss. They are particularly known to cause cancer (tumors) in various organs and tissues such as the liver, lungs, nasal cavity, esophagus, pancreas, stomach, urinary bladder, colon, kidneys, and central nervous system. Additionally, N-nitrosamine impurities may contribute to the development of Alzheimer's and Parkinson's diseases and type-2 diabetes. Therefore, it is very important to control or avoid them by enhancing effective analytical methodologies using cutting-edge analytical techniques such as LC-MS, GC-MS, CE-MS, SFC, etc. Moreover, these analytical methods need to be sensitive and selective with suitable precision and accuracy, so that the actual amounts of N-nitrosamine impurities can be detected and quantified appropriately in drugs. Regulatory agencies such as the US FDA, EMA, ICH, WHO, etc. need to focus more on the hazards of N-nitrosamine impurities by providing guidance and regular updates to drug manufacturers and applicants. Similarly, drug manufacturers should be more vigilant to avoid nitrosating agents and secondary amines during the manufacturing processes. Numerous review articles have been published recently by various researchers, focusing on N-nitrosamine impurities found in previously notified products, including sartans, metformin, and ranitidine. These impurities have also been detected in a wide range of other products. Consequently, this review aims to concentrate on products recently reported to contain N-nitrosamine impurities. These products include rifampicin, champix, famotidine, nizatidine, atorvastatin, bumetanide, itraconazole, diovan, enalapril, propranolol, lisinopril, duloxetine, rivaroxaban, pioglitazones, glifizones, cilostazol, and sunitinib.

Heralded and Complete Interconversion Between W State and Knill–Laflamme–Milburn State via State‐Selective Reflection with Robust Fidelity

AbstractThe interconversion of different types of entangled states not only can realize the information transmission but also play a significant role in quantum information technologies, including increasing scalability and computational power, and reducing error rates. Here, two protocols for achieving a complete interconversion between W state and Knill–Laflamme–Milburn state assisted by the quantum dot (QD)‐cavity systems and common quantum control gates are proposed. In particular, the protocols employ a heralded approach strategically designed to predict potential failures and facilitate seamless interaction between the QD‐cavity system and photons with the help of a single photon detectors, enhancing experimental accessibility. Through extensive analyzes and evaluations of two protocols, the proposed two protocols achieve remarkable utilization rates of photons (i.e., unit in principle) and achieve near‐unit fidelities and high efficiencies in principle.

Classification and Novelty Detection of Tampered ICs Using ResCav

This paper investigates the capabilities of the resonant cavity system (ResCav) for detecting tampered integrated circuits (ICs) within supply chains. Prior research showcased ResCav’s ability to discern minor circuit variations, this study focuses on enhancing supervised classification results and introduces a one-class support vector machine (SVM) approach with a modified radial basis function kernel for novelty detection. Through finer hyperparameter tuning, the system achieves improved classification accuracy, demonstrating its potential to identify nuanced alterations with even higher precision and recall rates. Additionally, the application of a one-class SVM enables the detection of tampered ICs without reliance on labeled datasets, expanding utility in scenarios where access is limited to golden ICs. These advancements in ResCav’s capabilities signify progress in failure prevention methodologies, offering an efficient and non-destructive solution crucial for safeguarding against counterfeit and non-conforming components infiltrating critical supply chains.

Narrow linewidth optical feedback vertical cavity surface emitting lasers based on cholesteric liquid crystal

Abstract In this paper, we present a narrow linewidth vertical cavity surface emitting laser (VCSEL) based on cholesteric liquid crystal (CLC). We investigated the impact of incorporating optical feedback into the external cavity on the linewidth of VCSELs, and successfully utilized CLC film as the reflector for the external cavity. This enabled us to achieve mode control and linewidth compression in VCSELs through optical feedback. The linewidth of the optically feedbacked VCSEL was measured at different driving currents and oxidation apertures. Under the same oxidation aperture, when the driving current is 1.2 mA, the linewidth is compressed from 120.9 MHz to 55.97 MHz; when the driving current is 0.8 mA, the linewidth is compressed from 22.87 MHz to 12.68 MHz. When the driving current remains constant, the linewidth is compressed from 169.31 MHz to 72 MHz when the oxidation aperture is 7 μm; and from 39.13 MHz to 10 MHz, when the oxidation aperture is 3 μm. By validating the feasibility of employing CLC film as an external cavity reflector mirror, our findings offer new insights towards achieving narrow-linewidth external cavity systems, thereby laying an experimental foundation for subsequent high-quality and highly integrated LC optical feedback VCSELs.