Article
Physics, Multidisciplinary
Xingping Wang, Gang Zhao, Kang Jiao, Bing Chen, Ruifeng Kan, Zhenhua Cong, Jianguo Liu, Weiguang Ma
Summary: This article presents optical feedback cavity ringdown spectroscopy using a linear Fabry-Perot cavity and a cost-effective DFB laser. By utilizing optical feedback technique, the coupling efficiency is significantly improved, resulting in a high signal-to-noise ratio and detection sensitivity.
FRONTIERS IN PHYSICS
(2022)
Article
Chemistry, Physical
Jun Jiang, A. Daniel McCartt
Summary: The intracavity pump-probe, cavity ringdown detection demonstrated in a three-mirror, traveling-wave cavity offers high selectivity and sensitivity, making it suitable for trace-detection in the mid-IR region. The technique involves uncorrelated measurements of analyte and background cavity decay rates, providing immunity to empty-CRD drifts and spectral overlaps from non-target molecular transitions. Additionally, the background compensation capability and experimental flexibility enhance its utility for mid-IR trace-detection.
JOURNAL OF CHEMICAL PHYSICS
(2021)
Article
Physics, Fluids & Plasmas
Rongrong W. Cohen, Chuji Wang
Summary: We developed a Brewster angle-cavity ringdown spectroscopy system for low temperature plasma diagnostics, with a detection limit of 9.1 x 10(-5) for measuring gas species in solutions. By improving the design and reflectivity of the system, the detection limit can potentially be reduced to 10(-6) or lower. We measured the absorption cross sections of HgBr2 and H2O2 in aqueous solutions and characterized the temporal profiles of absorbance from plasma-interacted water, HgBr2, and H2O2 solutions. The results demonstrate that the new BA-CRDS system is a powerful tool for quantifying reactive plasma species in complex settings.
PLASMA SOURCES SCIENCE & TECHNOLOGY
(2023)
Article
Multidisciplinary Sciences
Wenjia Chen, Yiwen Ou, Chunfu Cheng, Yuanchang Zhu, Wen Xiao, Hui Lv
Summary: A novel active fiber cavity ringdown technique using frequency-shifted interferometry is proposed. It allows monitoring of external parameters in the space domain by measuring the ringdown distance. Compared to existing methods, this technique eliminates the need for pulsed laser and uses continuous-wave laser for improved stability and precision. A proof-of-concept magnetic field sensor achieved the highest sensitivity compared to time-domain methods.
SCIENTIFIC REPORTS
(2022)
Article
Biochemistry & Molecular Biology
Jing Li, Qingyuan Li, Xin Wei, Qing Chen, Meixiu Sun, Yingxin Li
Summary: Exhaled nitric oxide levels showed clinical value in diagnosing lung cancer patients, but are not sufficient as a standalone diagnostic tool. Other factors should be considered in developing a diagnostic model for lung cancer using breath analysis.
Article
Physics, Fluids & Plasmas
Samuel D. A. Rogers, Amelia Bond, Benjamin J. Rhodes, Robert Peverall, Gus Hancock, Grant A. D. Ritchie
Summary: The absolute number density of ground state oxygen atoms (O(P-3)) in a 100 mTorr oxygen plasma was measured using cavity ringdown spectroscopy. The dissociation fraction and electron density were found to increase as the operating power increased. Emission spectra and a kinetic model were used to analyze the changes in rotational heating of O-2 and determine the physical parameters. Despite the spatial inhomogeneity of the plasma, a volume averaged model was able to accurately reproduce previous measurements and infer reasonable values for electron temperature and number density.
PLASMA SOURCES SCIENCE & TECHNOLOGY
(2022)
Article
Chemistry, Physical
M. Bermudez-Montana, M. Rodriguez-Arcos, M. Carvajal, C. Ostertag-Henning, R. Lemus
Summary: A polyad-conserving algebraic model is applied to study the vibrational excitations of asymmetric isotopologues of CO2. By considering the minimum subspace of states and the Fermi interaction, the model provides estimations of force constants and a local mode scheme for the system. The model is validated by comparing the results with experimental data.
JOURNAL OF PHYSICAL CHEMISTRY A
(2023)
Article
Engineering, Environmental
C. F. Martins, L. A. Neves, R. Chagas, L. M. Ferreira, C. A. M. Afonso, I. M. Coelhoso, J. G. Crespo, J. PB. Mota
Summary: This study investigates the absorption of carbon dioxide (CO2) by ionic liquids (ILs) with quaternary ammonium cations combined with biocompatible anions from renewable sources. The research combines theoretical modeling and experimental analysis to understand the absorption characteristics and dynamics. Experimental validation of the proposed model provides insights for designing new absorption processes for CO2 capture.
CHEMICAL ENGINEERING JOURNAL
(2021)
Article
Physics, Applied
A. S. C. Nave, J. R. Wubs, J. H. van Helden
Summary: This study demonstrates the use of cavity ringdown spectroscopy to detect and quantify Ar-2* in the effluent of a cold atmospheric plasma jet. The density distribution of Ar-2* in the kINPen-Sci effluent was determined.
APPLIED PHYSICS LETTERS
(2023)
Article
Optics
Yijie Ren, Changxiang Yan, Xiamiao Zhang, Chunhui Hu
Summary: This paper investigates the resonant coupling phenomenon in resonant cavities and reveals the same excitation factors of resonant coupling under different environmental perturbations. The resonant coupling characteristics of middle-order modes are analyzed through experiments, and a preferential coupling model is proposed. This research is important for understanding and controlling resonant coupling in cavities.
Article
Physics, Applied
Ryohei Terabayashi, Keisuke Saito, Volker Sonnenschein, Yuki Okuyama, Kazuki Iwamoto, Kazune Mano, Yuta Kawashima, Tetsuo Furumiya, Koji Tojo, Shinichi Ninomiya, Kenji Yoshida, Hideki Tomita
Summary: This paper reports a high precision trace analysis technique for gas molecules using mid-infrared laser absorption spectroscopy with a high-finesse optical cavity. The optical detection of radiocarbon (C-14) based on the cavity ringdown spectroscopy with a quantum cascade laser has gained attention as an alternative to accelerator mass spectrometry. The authors present a compact-packaged narrow-linewidth QCL system utilizing resonant optical feedback and demonstrate its capability for rapid analysis of (CO2)-C-14.
JOURNAL OF APPLIED PHYSICS
(2022)
Article
Physics, Multidisciplinary
E. Fasci, S. Gravina, G. Porzio, A. Castrillo, L. Gianfrani
Summary: Doppler-free saturated-absorption Lamb dips were observed for weak vibration-rotation transitions of C2H2 using a frequency-comb assisted cavity ring-down spectrometer, enabling highly accurate measurements and providing a stringent test of the MARVEL method for acetylene.
NEW JOURNAL OF PHYSICS
(2021)
Article
Engineering, Environmental
Ruwini D. Rajapaksha, Mina W. Tehrani, Ana M. Rule, Charles C. Harb
Summary: The study introduces a novel analytical approach, rtCRDS, for rapid detection of oxidative products in e-cigarette aerosols, showing that common additives can increase the generation of oxidative products. Ethanol was identified as a major constituent in the three commercial Juul flavors.
ENVIRONMENTAL SCIENCE & TECHNOLOGY
(2021)
Article
Engineering, Environmental
John S. Loring, Odeta Qafoku, Christopher J. Thompson, Ashley S. McNeill, Monica Vasiliu, David A. Dixon, Quin R. S. Miller, B. Peter McGrail, Kevin M. Rosso, Eugene S. Ilton, Herbert T. Schaef
Summary: The study found that under different CO2/CH4 ratios, different montmorillonites exhibit different swelling behaviors. CO2 facilitates the expansion of Na-clay, while CH4 cannot induce expansion. For Cs-clay, even in the absence of H2O, CO2 can cause expansion.
ENVIRONMENTAL SCIENCE & TECHNOLOGY
(2021)
Article
Instruments & Instrumentation
Wei Wei, Alonso Castro
Summary: In this study, cavity ring-down spectroscopy (CRDS) was successfully applied to study the Er-166 isotope in an atomic beam. By using a tuned diode laser and a high-finesse ring-down optical cavity, absorbance measurements of erbium atoms were conducted with high precision. This work demonstrates the ability to study dilute atomic beams of refractory materials accurately using CRDS.
APPLIED SPECTROSCOPY
(2023)
Article
Optics
Jianbao Zhao, Brant E. Billinghurst, Paul L. Raston
Summary: The far-infrared spectrum of room temperature formic acid labeled with 13C has been recorded and analyzed, leading to the determination of accurate line positions and predictions relevant to Earth's atmosphere and interstellar sources.
JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER
(2024)
Article
Optics
Semen Vasilchenko, Alexander Solodov, Oleg Egorov, Vladimir Tyuterev
Summary: Ozone plays a crucial role in atmospheric chemistry and radiative processes, and it may serve as a potential biosignature species in exoplanetary observations. This study utilized a continuous-wave cavity-ring-down spectrometer to accurately measure the absorption cross-sections of ozone in the near-infrared range. The results provide more precise data and have potential applications in atmospheric research.
JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER
(2024)
Article
Optics
Baorui Huang, Bo Peng, Qifeng Ren, Sheng Liao
Summary: This study utilizes the polarization bidirectional reflectance distribution function (p-BRDF) model derived from the microfacet theory to analyze the spectral p-BRDF of a brass surface. The results show that factors such as polarization state, wavelength, surface roughness, and permittivity have a significant impact on the distribution of BRDF on the object surface.
JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER
(2024)
Article
Optics
Qingwei Duan, Jiajie Wang, Qiwei Li, Xiang'e Han, Kuan Fang Ren
Summary: This paper introduces the applications of the generalized Lorenz-Mie theory (GLMT) and the vectorial complex ray model (VCRM) in the interaction between beams and particles. By comparing the experimental results, it is found that VCRM performs well in Gaussian beam scattering problems, providing a new method for studying the scattering of shaped beams by large particles/objects of any shape.
JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER
(2024)
Article
Optics
Yuefan Du, Xiaoping Li, Lei Shi, Fangyan Li, Shurong Yuan
Summary: This study proposes a physics-constrained model that utilizes the distribution characteristics of gas spectral parameters to predict spectral parameters for unknown wavelengths. Experimental results show that the model improves prediction accuracy and increases the data volume of gas spectral parameters by 4-5 times.
JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER
(2024)
Article
Optics
Laurentius Windholz, Imran Siddiqui, Shamim Khan, Syed Tanweer Iqbal
Summary: In this study, we report the discovery of two energy levels of the Pr atom that exhibit strong J-mixing, as well as the observed hyperfine structure patterns. The composition of wave functions, in addition to J-values, plays a crucial role in determining the appearance of these patterns.
JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER
(2024)
Article
Optics
Matthias Germann, Adrian Hjalten, Jonathan Tennyson, Sergei N. Yurchenko, Iouli E. Gordon, Christian Pett, Isak Silander, Karol Krzempek, Arkadiusz Hudzikowski, Aleksander Gluszek, Grzegorz Sobon, Aleksandra Foltynowicz
Summary: In this study, optical frequency comb Fourier transform spectroscopy was used to record the spectroscopic data of formaldehyde in a specific frequency range. The line positions and intensities of rovibrational transitions were obtained through line-by-line fitting. By incorporating these accurate line positions into the analysis, more energy levels and rovibrational transitions were predicted with reduced uncertainties in the H2CO spectrum.
JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER
(2024)
Article
Optics
Leonardo A. Ambrosio, Jhonas O. de Sarro, Gerard Gouesbet
Summary: This study derives a polychromatic version of the generalized Lorenz-Mie theory stricto sensu (GLMT) by expanding arbitrary time-dependent fields into partial waves using Bromwich scalar potentials. The new formalism introduces field shape spectra (FSSs) which are intrinsically frequency-dependent, modifying and redefining the physical quantities expressed in the monochromatic GLMT.
JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER
(2024)
Article
Optics
Patrick C. Chaumet
Summary: The paper proposes two new methods (IDR(s) and GPBiCGstab(L)) for computing the electromagnetic diffraction of objects larger than the wavelength. It is found that IDR(s) can reduce computation time but may not converge in some cases, while GPBiCGstab(L) always converges and also reduces computation time compared to QMR, GPBiCG, and BiCGstab.
JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER
(2024)
Article
Optics
Antigoni Kleanthous, Anthony J. Baran, Timo Betcke, David P. Hewett, Christopher D. Westbrook
Summary: To improve weather and climate models, it is important to accurately calculate the single-scattering properties of randomly oriented complex atmospheric ice crystals. This study applies Boundary Element Method (BEM) to calculate these properties in the microwave and sub-millimeter region of the electromagnetic spectrum for all-sky data assimilation. The results show that BEM can accurately compute the scattering properties of complex ice aggregates, which is crucial for weather and climate models.
JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER
(2024)
Article
Optics
Ben Niu, Yanting Li, Gang Xiong, Jihui Chen, Zhimin Hu, Yunqing Fu, Yaming Zou, Chongyang Chen, Ke Yao
Summary: This study presents both experimental and theoretical analysis of the 4d 2D5/2 -> 2D3/2 magnetic dipole transition in Rb-like ions. The correlation between the theoretical and experimental findings is observed, and it is illustrated that the contribution of the core-valence correlation is pivotal for the fine structure splittings.
JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER
(2024)
Article
Optics
James A. Lock, Gunther P. Konnen, Philip Laven
Summary: Researchers have derived an analytical generalization of Airy theory that provides a more accurate approximation for the primary rainbow, but still has limitations for the second-order rainbow and beyond.
JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER
(2024)
Article
Optics
Shixiong Wu, Xuebang Gao, Xuqiang Dou, Li Xie
Summary: In this paper, an indoor experimental study was conducted to investigate the optical attenuation caused by sand/dust storms at different relative humidity levels. It was found that the hygroscopic growth of sand/dust particles has a significant effect on optical attenuation when the relative humidity is above 60%. Based on the double-parameter Kasten model, a proposed optical attenuation model takes into account visibility, particle size, relative humidity, and optical wavelength. Numerical calculations considering the hygroscopicity effect were also performed, and the results were in agreement with the experimental data.
JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER
(2024)
Article
Optics
Zhimin Yang, Jaeman Song, Bong Jae Lee
Summary: In this study, we analyze TPX cells operating in the self-sustaining circuit and examine the effects of different bandgaps on their performance. The results show that the bandgap energy of the LED must exceed that of the PV cell for the TPX cell to function in a self-sustaining parallel circuit. Additionally, a narrower bandgap energy for the PV cell and a wider bandgap energy for the LED can improve the performance of the TPX cell in the self-sustaining circuit.
JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER
(2024)