Article
Chemistry, Physical
Myles C. Silfies, Grzegorz Kowzan, Neomi Lewis, Thomas K. Allison
Summary: The article discusses a cavity-enhanced ultrafast transient absorption spectrometer, extending broadband all-optical ultrafast spectroscopy techniques to dilute beams of gas-phase molecules and clusters. Technical innovations behind the spectrometer and transient absorption data on two molecular systems for excited-state intramolecular proton transfer are presented.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2021)
Article
Chemistry, Physical
Panpan Ren, Chong Wang, Bo Yang, Lu Xing, Shenghan Wang, Zhiwei Men, Chenglin Sun
Summary: An anomalous enhanced stimulated Raman scattering phenomenon was observed in cyclohexane-benzene mixtures. The cross-pumping effect between the C-H stretching mode of cyclohexane and the C=C ring skeleton mode of benzene in the mixture resulted in the generation of two super-broadband radiations. This study demonstrates that energy transfer of intermolecular vibrational modes is a simple approach for generating supercontinuum coherent radiation.
JOURNAL OF CHEMICAL PHYSICS
(2023)
Article
Optics
Colin Sonnichsen, Patrick Brosseau, Cameron Reid, Patanjali Kambhampati
Summary: The system utilizes a commercial OPA to drive a hollow-core fiber, generating sub-10 fs pulses with output pulse energies in the range of 40-80 μJ. The system exhibits minimal power fluctuations, excellent mode quality, and well-behaved spectral phase at the output. By measuring the two-dimensional spectrum of CdSe quantum dots, the strength of this source is demonstrated, providing a substantial extension to the capabilities of CMDS.
Article
Optics
Haodong Zhang, Jing Luo, Saimei Hou, Zhanpeng Xu, Julian Evans, Sailing He
Summary: Incoherent broadband cavity-enhanced absorption spectroscopy (IBBCEAS) enables sensitive measurements of trace concentrations in liquid phase marine samples. The system provides high cavity enhancement factors and spectral resolution, allowing for concentration measurements of various biological and chemical substances, with potential applications in in situ ecological marine environmental monitoring.
Article
Chemistry, Analytical
Gaoxuan Wang, Lingshuo Meng, Qian Gou, Benjamin Hanoune, Suzanne Crumeyrolle, Thomas Fagniez, Cecile Coeur, Rony Akiki, Weidong Chen
Summary: A novel instrument based on broadband cavity-enhanced absorption spectroscopy has been developed for simultaneous measurements of NO2 concentration and particulate matter extinction. It shows good linear correlation (r2 > 0.90) with reference analyzers. The instrument has measurement limits of 230 pptv for NO2 in 40s and 1.24 Mm-1 for particulate matter extinction in 15s. This work provides a promising method for monitoring atmospheric gaseous compounds and particulate matter simultaneously.
ANALYTICAL CHEMISTRY
(2023)
Article
Physics, Applied
Qinxue Nie, Zhen Wang, Simone Borri, Paolo De Natale, Wei Ren
Summary: We have developed a swept cavity-enhanced photoacoustic spectroscopy system using a quartz tuning fork for highly sensitive and high-resolution molecular spectroscopy. By using a quantum cascade laser (QCL) and a dual-feedback Pound-Drever-Hall locking method, the QCL frequency is locked to a continuously swept optical cavity. With a 48-mm Fabry-Perot cavity and an off-beam quartz-enhanced photoacoustic spectroscopy module, ultra-sensitive gas detection is achieved based on the doubly resonant photoacoustic effect.
APPLIED PHYSICS LETTERS
(2023)
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
Dmitry A. Kozak, Nathan F. Tyndall, Marcel W. Pruessner, William S. Rabinovich, Todd H. Stievater
Summary: Germanium-on-silicon (GOS) is the leading platform for foundry-based long-wave infrared photonic integrated circuits (LWIR PICs) due to its CMOS compatibility and lack of oxides. Ring resonances and thermo-optic tunability in germanium-on-silicon waveguides have been described, showing potential for photonic integration and waveguide spectroscopy across a wide range of infrared wavelengths.
Article
Chemistry, Analytical
Imogen M. Fermor-Worth, Catalin Chimerel
Summary: Absorption spectroscopy is widely used for analysis due to its label-free nature, but it has limited sensitivity in small liquid samples with short absorption pathlengths. This study presents a novel concept for an ultrasensitive broadband absorption spectrometer optimized for thin liquid films. By implementing an optical cavity on a fiber-based absorption spectrometer, light is circulated multiple times through the sample to enhance sensitivity.
Article
Optics
Yohan Yoon, Christopher J. Breshike, Christopher A. Kendziora, Robert Furstenberg, R. Andrew McGill
Summary: The study developed a simultaneous grating spectroscopy technique using a broadband IR laser source capable of real-time detection of moving targets. By optimizing the laser operating conditions based on a detailed understanding of the broadband source, the technique successfully discriminated the spectral features of samples, showing discrete peaks comparable to FTIR reference spectra.
Article
Engineering, Electrical & Electronic
Qixin He, Chuantao Zheng, Weilin Ye, Frank K. Tittel
Summary: In this work, a technique called periodical mode-locked cavity-enhanced absorption spectroscopy (PML-CEAS) was proposed for detecting multiple gases using a single-mode diode laser. The technique utilizes periodic mode-locking to achieve rapid and stable frequency locking at different cavity modes, improving the response speed for multigas detection. Experimental measurements of C2H2 and H2O were conducted using a fiber-coupled distributed feedback (DFB) laser and a designed Fabry-Perot cavity as the gas absorption cell. The proposed technique addresses the limitations of traditional CEAS and has promising applications in environmental monitoring, breath analysis, and industrial settings.
IEEE SENSORS JOURNAL
(2023)
Article
Engineering, Electrical & Electronic
Qixin He, Chuantao Zheng, Weilin Ye, Frank K. Tittel
Summary: In this study, a general technique called periodical mode-locked cavity-enhanced absorption spectroscopy (PML-CEAS) is proposed for detecting multiple gases using a single-mode diode laser. The technique involves periodical mode-locking to achieve rapid and stable frequency locking at different cavity modes, interrupting and relocking the laser frequency. A multigas detection strategy is also proposed to improve the system's response speed. The effectiveness of the technique is verified through the detection of C2H2 and H2O using a fiber-coupled distributed feedback (DFB) laser, and the performance of the system is evaluated.
IEEE SENSORS JOURNAL
(2023)
Article
Meteorology & Atmospheric Sciences
Caroline C. C. Womack, Steven S. S. Brown, Steven J. Ciciora, Ru-Shan Gao, Richard J. McLaughlin, Michael A. Robinson, Yinon Rudich, Rebecca A. Washenfelder
Summary: This article describes the design and performance of a lightweight broadband cavity-enhanced spectrometer for NO2 measurements on uncrewed aerial vehicles and light aircraft. The instrument demonstrates high precision and accuracy, with low weight and power consumption.
ATMOSPHERIC MEASUREMENT TECHNIQUES
(2022)
Article
Physics, Multidisciplinary
Zhang He-Lu, Qin Min, Fang Wu, Tang Ke, Duan Jun, Meng Fan-Hao, Shao Dou, Hua Hui, Liao Zhi-Tang, Xie Pin-Hua
Summary: The quantitative method of iodine monoxide radical (TO) is described in this paper using incoherent broadband cavity enhanced absorption spectroscopy (IBBCEAS) in the 435-465 nm band. Evaluation of parameters and calibration of the mirror reflectivity at the absorption peak are essential for accurately determining the concentration of IO. Experimental results show high sensitivity of the system in different concentration ranges and effective calibration of IO losses in the sampling tube.
ACTA PHYSICA SINICA
(2021)
Article
Chemistry, Analytical
Pinyi Wang, Weigen Chen, Jianxin Wang, Feng Zhou, Jin Hu, Zhixian Zhang, Fu Wan
Summary: The efficiency of cavity-enhanced Raman spectroscopy (CERS) was demonstrated with a folded multipass cavity for detecting hazardous gases in the atmosphere. By optimizing the number of intracavity beams and designing cavity parameters, ppb-level Raman gas sensing for various explosive and toxic gases was achieved at atmospheric pressure within a short exposure time. The CERS apparatus offers simultaneous detection of multiple gases with ultrahigh sensitivity and selectivity, showing great potential for environmental safety monitoring.
ANALYTICAL CHEMISTRY
(2021)
Article
Chemistry, Physical
Nathan A. Seifert, Daniel P. Zaleski, Robert Fehnel, Mausumi Goswami, Brooks H. Pate, Kevin K. Lehmann, Helen O. Leung, Mark D. Marshall, John F. Stanton
JOURNAL OF CHEMICAL PHYSICS
(2017)
Article
Chemistry, Physical
Kevin K. Lehmann
JOURNAL OF CHEMICAL PHYSICS
(2018)
Article
Optics
Juho Karhu, Kevin Lehmann, Markku Vainio, Markus Metsala, Lauri Halonen
Article
Chemistry, Physical
Kevin K. Lehmann
JOURNAL OF CHEMICAL PHYSICS
(2019)
Correction
Chemistry, Physical
Kevin K. Lehmann
JOURNAL OF CHEMICAL PHYSICS
(2020)
Article
Optics
Kevin K. Lehmann
JOURNAL OF THE OPTICAL SOCIETY OF AMERICA B-OPTICAL PHYSICS
(2020)
Article
Chemistry, Physical
Kevin K. Lehmann
Summary: This article derived an analytic line shape for degenerate two-photon transition under specific conditions, expressed in reduced units and subjected to numerical calculations.
JOURNAL OF CHEMICAL PHYSICS
(2021)
Article
Physics, Multidisciplinary
Aleksandra Foltynowicz, Lucile Rutkowski, Isak Silander, Alexandra C. Johansson, Vinicius Silva de Oliveira, Ove Axner, Grzegorz Sobon, Tadeusz Martynkien, Pawel Mergo, Kevin K. Lehmann
Summary: This study reports the first measurement of sub-Doppler molecular response using a frequency comb as a probe in optical-optical double-resonance spectroscopy. They utilized a 3.3 μm continuous wave pump and a 1.67 μm comb probe to detect sub-Doppler transitions to the 2 nu(3) and 3 nu(3) bands of methane. The transition frequencies to the 3 nu(3) band showed good agreement with the TheoReTS line list.
PHYSICAL REVIEW LETTERS
(2021)
Proceedings Paper
Engineering, Electrical & Electronic
Gang Zhao, D. Michelle Bailey, Adam J. Fleisher, Joseph T. Hodges, Kevin K. Lehmann
Summary: This study demonstrates Doppler-free two-photon cavity ring-down spectroscopy using a narrow linewidth quantum cascade laser locked to a high-finesse cavity, and reports the two-photon absorption of N2O-N-14-O-16 at around 2207.507 cm(-1).
2021 CONFERENCE ON LASERS AND ELECTRO-OPTICS (CLEO)
(2021)
Proceedings Paper
Engineering, Electrical & Electronic
Vinicius Silva de Oliveira, Isak Silander, Lucile Rutkowski, Grzegorz Sobo, Ove Axner, Kevin K. Lehmann, Aleksandra Foltynowicz
Summary: By implementing a cavity to enhance absorption, we achieved two orders of magnitude better sensitivity in a double-resonance measurement of methane transitions compared to previous work using a single-pass cell, with a 15 times shorter acquisition time.
2021 CONFERENCE ON LASERS AND ELECTRO-OPTICS (CLEO)
(2021)
Proceedings Paper
Engineering, Electrical & Electronic
Vinicius Silva de Oliveira, Isak Silander, Lucile Rutkowski, Alexandra C. Johansson, Grzegorz Sobon, Ove Axner, Kevin K. Lehmann, Aleksandra Foltynowicz
2021 CONFERENCE ON LASERS AND ELECTRO-OPTICS EUROPE & EUROPEAN QUANTUM ELECTRONICS CONFERENCE (CLEO/EUROPE-EQEC)
(2021)
Article
Optics
Aleksandra Foltynowicz, Lucile Rutkowski, Isak Silander, Alexandra C. Johansson, Vinicius Silva de Oliveira, Ove Axner, Grzegorz Sobon, Tadeusz Martynkien, Pawel Mergo, Kevin K. Lehmann
Summary: Optical-optical double-resonance spectroscopy technique was used to measure sub-Doppler transitions in highly excited molecular states. The study focused on methane molecules, with results showing good agreement with theoretical predictions.
Proceedings Paper
Engineering, Electrical & Electronic
Aleksandra Foltynowicz, Lucile Rutkowski, Isak Silander, Alexandra C. Johansson, Vinicius Silva de Oliveira, Ove Axner, Grzegorz Sobon, Tadeusz Martynkien, Pawel Mergo, Kevin K. Lehmann
2020 CONFERENCE ON LASERS AND ELECTRO-OPTICS (CLEO)
(2020)
Article
Optics
Gang Zhao, D. Michelle Bailey, Adam J. Fleisher, Joseph T. Hodges, Kevin K. Lehmann
Article
Business, Finance
Mikhail Beketov, Kevin Lehmann, Manuel Wittke
JOURNAL OF ASSET MANAGEMENT
(2018)