Article
Spectroscopy
Reagan R. D. Weeks, Mark C. Phillips, Yu Zhang, Sivanandan S. Harilal, R. Jason Jones
Summary: The study utilized dual-comb spectroscopy to measure the absorption spectra of gadolinium, determining the oscillator strengths of 43 transitions, 19 of which were previously unreported. By repeatedly measuring atomic absorption, the research improved confidence in the results.
SPECTROCHIMICA ACTA PART B-ATOMIC SPECTROSCOPY
(2021)
Article
Optics
J. Pupeikis, B. Willenberg, S. L. Camenzind, A. Benayad, P. Camy, C. R. Phillips, U. Keller
Summary: Single-cavity dual-comb lasers are a new type of ultrafast lasers with wide application potential. The researchers propose a method for multiplexing a single laser cavity to support noise-correlated modes, achieving high-energy, short-pulse, and low-timing-noise laser output.
Article
Optics
Takahiko Mizuno, Yoshiaki Nakajima, Yuya Hata, Takuya Tsuda, Akifumi Asahara, Takashi Kato, Takeo Minamikawa, Takeshi Yasui, Kaoru Minoshima
Summary: Dual-comb microscopy (DCM) is an imaging modality based on optical-frequency-comb (OFC) mode, providing scan-less full-field imaging and confocal amplitude and phase imaging. The practicality of DCM is limited by the complexity and costs of fully frequency-stabilized OFC sources. This study introduces a low-complexity OFC source for DCM using a bidirectional single-cavity dual-comb fiber laser (SCDCFL), and demonstrates the effectiveness of computational image correction in reducing image blur. The proposed method enhances DCM generality and practicality, suggesting a possibility to extend computational image correction to dynamic objects.
Article
Optics
Maciej Kowalczyk, Lukasz A. Sterczewski, Xuzhao Zhang, Valentin Petrov, Jaroslaw Sotor
Summary: This article reports the first solid-state dual-comb mode-locked laser that can simultaneously operate in different dispersion regimes. By exploiting the intrinsic polarization multiplexing in a birefringent gain medium, the laser emits two pulse trains with a small repetition rate offset. Dual pulse generation with different durations is achieved by controlling the net cavity group delay dispersion.
Article
Optics
Maciej Kowalczyk, Lukasz Sterczewski, Xuzhao Zhang, Valentin Petrov, Zhengping Wang, Jaroslaw Sotor
Summary: This study demonstrates a versatile concept for low-noise dual-comb generation from a single-cavity femtosecond solid-state laser, achieving the lowest relative noise ever demonstrated for a bulk dual-comb source, enabling free-running mode-resolved spectroscopic measurements over a second. The developed dual-comb generation technique can be applied to any solid-state laser exploiting a birefringent active crystal, paving the way toward a new class of highly coherent, single-cavity, dual-comb laser sources operating in various spectral regions.
LASER & PHOTONICS REVIEWS
(2021)
Article
Multidisciplinary Sciences
Kilian Fritsch, Tobias Hofer, Jonathan Brons, Maksim Iandulskii, Ka Fai Mak, Zaijun Chen, Nathalie Picque, Oleg Pronin
Summary: The authors demonstrate a fully passive scheme of generating high-power dual-combs from a thin-disc gain medium. Compared to traditional dual-comb sources, this system achieves higher peak power and average power, addressing practical applications and frequency conversion challenges.
NATURE COMMUNICATIONS
(2022)
Article
Optics
Neeraj Prakash, Shu-Wei Huang, Bowen Li
Summary: This paper introduces a novel counterpropagating all-normal dispersion (CANDi) fiber laser and investigates its relative timing jitter (RTJ). The experiment reveals that the dominant factor affecting the RTJ is the pump relative intensity noise (RIN). Solutions to reduce the jitter are discussed.
Article
Optics
Justinas Pupeikis, Benjamin Willenberg, Francois Bruno, Mike Hettich, Alexander Nussbaum-Lapping, Matthias Golling, Carolin P. Bauer, Sandro L. Camenzind, Abdelmjid Benayad, Patrice Camy, Bertrand Audoin, Christopher R. Phillips, Ursula Keller
Summary: The research team developed a free-running 80-MHz dual-comb polarization-multiplexed solid-state laser for picosecond ultrasonic measurements with satisfactory results. They revealed the ultrasonic signatures in semiconductor multi-quantum-well structures and compared them with other techniques. The study showed that this free-running dual-comb laser performs well in picosecond ultrasonic measurements and offers cost and complexity savings.
Article
Optics
Marko M. Krstic, Jasna Crnjanski, Mladen Z. Banovic, Ivana S. Vasiljevic, Dejan M. Gvozdic
Summary: This paper presents a simple and power efficient scheme for dual optical frequency comb generation on a single directly modulated semiconductor laser. The scheme can generate dual combs with teeth pairs within 20 dB margin spanning up to 116 GHz with power per teeth pair up to 8.8 mu W, as well as combs with 40 GHz span comprising ultraflat teeth pairs with flatness of the order of 1 dB.
Correction
Optics
C. R. Phillips, B. Willenberg, A. Nussbaum-Lapping, F. Callegari, S. L. Camenzind, J. Pupeikis, U. Keller
Summary: This erratum corrects a typographical error in equation (8) of our published paper [Opt. Express 31, 7103 (2023)]. All the calculations used the correct equation, so all the results and conclusions remain unchanged.
Article
Engineering, Multidisciplinary
D. Charczun, A. Nishiyama, G. Kowzan, A. Cygan, T. Voumard, T. Wildi, T. Herr, V Brasch, D. Lisak, P. Maslowski
Summary: This study demonstrates the first dual-comb realization of cavity mode-width and mode-dispersion spectroscopies, achieving high speed and resolution. By interleaving multiple spectra, it is possible to measure simultaneously the loss and dispersion of both the cavity and the intracavity medium, with potential applications in various fields.
Article
Physics, Applied
G. Q. Hu, L. Q. Zhu, G. K. Sun, L. L. Lu, R. You, Y. Liu, W. He, M. L. Dong
Summary: This study investigates the emission of free-running dual-comb pulses with overlapping spectra and controlled repetition rate difference in a single birefringent fiber cavity. Various mechanisms for soliton formation are observed and validated, enabling switchable and tunable dual-comb pulse emissions. The study highlights the potential of simplifying the amplification system and single-cavity dual-comb source with overlapping spectra and passive mutual coherence between pulses.
APPLIED PHYSICS LETTERS
(2022)
Article
Optics
Jacob Nurnberg, Benjamin Willenberg, Christopher R. Phillips, Ursula Keller
Summary: This paper demonstrates laser ranging using free-running dual-comb semiconductor and solid-state laser oscillators. Through clever polarization duplexing, dual-comb operation within a single cavity is achieved, and ranging experiments were conducted with two implementations.
Article
Physics, Applied
Elizabeth J. Kautz, Mark C. Phillips, Sivanandan S. Harilal
Summary: In this study, laser-induced fluorescence (LIF) was utilized to enhance emission signals from plasma generated by ultrafast laser filaments on an Al 6061 alloy target. This approach effectively reduced self-reversal features and improved detection sensitivity for standoff and remote element and isotope detection. The findings highlight the potential of LIF for boosting signal-to-noise ratio in filament-induced breakdown spectroscopy applications.
JOURNAL OF APPLIED PHYSICS
(2021)
Article
Optics
Jonas Westberg, Chu C. Teng, Yifeng Chen, Jie Liu, Link Patrick, Linhan Shen, Michael Soskind, Gerard Wysocki
Summary: This article presents a mobile mid-infrared quantum cascade laser dual-comb spectrometer for the detection of chemical releases, which has high temporal and spatial resolution and can cover large areas. Field tests in downtown Boston demonstrate its effectiveness in identifying and quantifying chemical plumes. This type of sensor will be a valuable complement to existing optical sensors for monitoring gas leaks, assessing air quality, and localizing clandestine chemical production.
Article
Physics, Applied
S. S. Harilal, E. J. Kautz, M. C. Phillips
Summary: We present the spatiotemporal evolution of emission and absorption signatures of Al species in a nanosecond laser-produced plasma (LPP). The measurements were conducted using time-of-flight (TOF) emission and laser absorption spectroscopy, providing kinetic information of the excited state and ground state populations. Multiple peaks were observed in the temporal profiles of the emission and absorption signatures, corresponding to different spatial locations and times. The absorption spectra were used to measure linewidths, column density, and kinetic temperature, while the emission spectra were used to measure excitation temperature. The combination of TOF and spectral measurements offers a more complete understanding of the spatiotemporal dynamics of the LPP.
JOURNAL OF APPLIED PHYSICS
(2022)
Article
Optics
Ryan T. Rhoades, Reagan R. D. Weeks, Seth E. Erickson, Caroline Lecaplain, Sivanandan S. Harilal, Mark C. Phillips, R. Jason Jones
Summary: The broadband and high-resolution absorption spectra of molecular cerium oxide (CeO) are obtained using dual-comb spectroscopy in a laser-produced plasma. Simultaneous measurements of Ce and CeO are used to investigate the time-resolved dynamics of the system. The high spectral resolution allows for the simultaneous detection of numerous closely spaced rotational transitions in complex CeO bands.
Article
Nanoscience & Nanotechnology
Elizabeth J. Kautz, Sten Lambeets, Jacqueline Royer, Daniel E. Perea, Sivanandan S. Harilal, Arun Devaraj
Summary: Compositional partitioning during uranium alloy oxidation was studied using complementary ex situ-in situ atom probe tomography. The results revealed the formation of hypostoichiometric uranium oxide under all environmental conditions. Redistribution of molybdenum, hydrogen, carbon, and silicon impurities was observed, affecting the composition of the oxide film.
SCRIPTA MATERIALIA
(2022)
Article
Physics, Applied
Reagan R. D. Weeks, Yu Zhang, Sivanandan S. Harilal, Mark C. Phillips, R. Jason Jones
Summary: Dual-comb spectroscopy (DCS) is a novel diagnostic tool for analyzing excitation temperatures and column densities in laser-produced plasmas (LPPs). In this study, DCS was used to measure the excitation temperatures and column densities of Nd, Gd, and Fe in a multielement alloy. The results showed that the excitation temperatures of Nd I and Gd I were consistent at all time-delays, while the Fe I temperature was higher and the column density ratios varied with delay.
JOURNAL OF APPLIED PHYSICS
(2022)
Review
Physics, Multidisciplinary
S. S. Harilal, M. C. Phillips, D. H. Froula, K. K. Anoop, R. C. Issac, F. N. Beg
Summary: This article provides an overview of optical diagnostic tools frequently used for the characterization of laser-produced plasmas (LPPs), focusing on the low to moderate laser intensity regime. The review emphasizes the techniques, assumptions, and challenges associated with these diagnostic tools.
REVIEWS OF MODERN PHYSICS
(2022)
Article
Physics, Fluids & Plasmas
Yingchao Huang, Sivanandan S. Harilal, Abdul Bais, Amina E. Hussein
Summary: Optical emission spectroscopy, known as LIBS, is a rapid soil analysis technique. However, challenges like matrix effects and quantification issues need further study, especially for heterogeneous samples like soils. Advancements in machine learning can overcome these challenges and enhance the potential of LIBS in soil analysis.
IEEE TRANSACTIONS ON PLASMA SCIENCE
(2023)
Editorial Material
Physics, Fluids & Plasmas
Sivanandan S. S. Harilal, Uri Shumlak, Justin Little
Summary: ICOPS is an annual conference that brings together plasma physics researchers to discuss various applications of plasma science and technology. It is organized by the PSAC of the IEEE NPSS.
IEEE TRANSACTIONS ON PLASMA SCIENCE
(2023)
Article
Physics, Applied
M. P. Polek, E. J. Kautz, T. Ahmed, B. R. Kowash, F. N. Beg, S. S. Harilal
Summary: The ion emission properties of laser-produced plasmas were investigated with varying laser intensities and angles. The ion profiles consist of multiple peaks and each peak follows a unique trend as a function of laser intensity, angle, and distance. Simple analytical models can explain the ion properties, and the variations in ion velocity and density agree with theoretical models of acceleration, expansion, and plasma flow.
JOURNAL OF APPLIED PHYSICS
(2023)
Article
Optics
Mark C. Phillips, Elizabeth J. Kautz, Sivanandan S. Harilal
Summary: High-resolution tunable laser absorption spectroscopy is used to measure time-resolved absorption spectra for six neutral uranium transitions in a laser-produced plasma. Analysis of the spectra shows that kinetic temperatures are similar for all six transitions, but excitation temperatures are higher than kinetic temperatures from 10-100 microseconds, indicating departures from local thermodynamic equilibrium.
Article
Physics, Fluids & Plasmas
Elizabeth J. J. Kautz, Mark C. C. Phillips, Prasoon K. K. Diwakar, Alla Zelenyuk, Sivanandan S. S. Harilal
Summary: The kinetics of ion and neutral atom emissions in nanosecond laser-produced plasmas were investigated for different metal targets and an alloy. It was found that the most probable velocities of ions and atoms decrease with increasing atomic mass. The velocities of ions from the alloy target represent a weighted average of all ions. Both ions and atoms exhibit decreased velocities with increasing heat of vaporization and melting temperature. The kinetic energies of neutral atoms from pure metal targets have some variability with atomic mass, whereas those from the alloy target are more similar, possibly due to collisions between species in the Knudsen layer.
PHYSICS OF PLASMAS
(2023)
Article
Spectroscopy
Elizabeth J. Kautz, Mark C. Phillips, Sivanandan S. Harilal
Summary: We measured the time-resolved emission spectroscopic signatures of Ta, TaO, and TaN from a laser-produced plasma. Varying the O2/N2 percentages in the gaseous environment, we observed that Ta oxide emission is more prominent in later stages of plasma evolution, while strong atomic emission is present in the early stages in air. The emission intensity of TaO increases, and its peak intensity appears earlier with increasing O2 availability. Additionally, we found that the presence of O2 favors TaO formation over TaN in the plasma chemistry.
SPECTROCHIMICA ACTA PART B-ATOMIC SPECTROSCOPY
(2023)
Article
Chemistry, Physical
Elizabeth J. Kautz, Alla Zelenyuk, Bharat Gwalani, Matthew J. Olszta, Mark C. Phillips, Manuel J. Manard, Clare W. Kimblin, Sivanandan S. Harilal
Summary: The role of ambient oxygen gas in laser ablation plumes on molecular and nanoparticle formation and agglomeration was studied. The presence of O2 impacts the emission spectra, cluster size, and agglomeration behavior of nanoparticles. These findings are important in understanding debris formation in an explosion event.
JOURNAL OF CHEMICAL PHYSICS
(2023)
Article
Optics
Elizabeth J. Kautz, Annie Xu, Ajay V. Harilal, Mathew P. Polek, Andrew M. Casella, David J. Senor, Sivanandan S. Harilal
Summary: Laser induced breakdown spectroscopy is a promising method for the rapid analysis of Li and its isotopes. However, challenges arise from spectral broadening, fine and hyperfine structures, and self-reversal effects. This study investigates the impact of ambient gases on line broadening and self-reversal of Li isotopes in laser produced plasmas. The results show that lower pressures and optimized plasma conditions can improve the accuracy of isotopic analysis.
Article
Chemistry, Physical
Elizabeth J. Kautz, Alla Zelenyuk, Bharat Gwalani, Mark C. Phillips, Sivanandan S. Harilal
Summary: This study investigates the evolution from gas-phase oxidation to nanoparticle and agglomerate formation in nanosecond laser-produced plasmas of a multi-principal element alloy target. The results highlight the importance of the target composition in the formation of gas-phase molecules, as well as the morphology, composition, and structure of nanoparticles and agglomerates formed.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2022)
Article
Physics, Fluids & Plasmas
Elizabeth J. Kautz, Mark C. Phillips, Alla Zelenyuk, Sivanandan S. Harilal
Summary: The temporal evolution of atoms and molecules in a laser-produced plasma from metal targets was investigated using optical emission spectroscopy. The results showed that the partial pressure of O-2 strongly influences spectral features and molecular formation in laser-produced plasmas.
PHYSICS OF PLASMAS
(2022)