Article
Optics
Farid Ullah Khan, Aldo Moreno-Oyervides, Oscar Elias Bonilla-Manrique, Pedro Martin-Mateos
Summary: High-performance hyperspectral imaging is in high demand due to its wide range of capabilities. However, traditional systems have limitations in resolving narrow spectral features. In this study, we introduce the first hyperspectral dual-comb imaging system with sub-GHz optical resolutions and fast acquisition rates in the mid-infrared region.
OPTICS AND LASERS IN ENGINEERING
(2023)
Article
Thermodynamics
Amanda S. Makowiecki, Daniel Herman, Nazanin Hoghooghi, Elizabeth F. Strong, Ryan K. Cole, Gabe Ycas, Fabrizio R. Giorgetta, Caelan B. Lapointe, Jeffrey F. Glusman, John W. Daily, Peter E. Hamlington, Nathan R. Newbury, Ian R. Coddington, Gregory B. Rieker
Summary: This study demonstrates the application of mode-locked mid-infrared dual frequency comb spectroscopy for combustion analysis. By using the broadband spectrometer with fine spectral resolution and broad bandwidth, precise measurements of various gases during wood combustion process can be obtained.
PROCEEDINGS OF THE COMBUSTION INSTITUTE
(2021)
Article
Acoustics
Xinyi Ren, Ming Yan, Zhaoyang Wen, Hui Ma, Ran Li, Kun Huang, Heping Zeng
Summary: Photoacoustic spectroscopy (PAS) using two optical combs offers broad bandwidths, high resolutions, fast acquisition speeds, and wavelength-independent detection. However, sensitivity and specificity are limited. In this study, we demonstrate comb-enabled PAS with enhanced sensitivity and nonlinear spectral hole-burning defined resolution, enabling trace detection and Doppler-free gas sensing.
Article
Chemistry, Analytical
Eduardo M. Paiva, Florian M. Schmidt
Summary: Mid-infrared photothermal microscopy is a valuable tool for chemical imaging with high spatial resolution. This study introduces a widefield mid-infrared photothermal heterodyne imaging technique using a digital frequency-domain lock-in filter for simultaneous multiharmonic demodulation of MIP signals. The technique achieves high sensitivity, spatial resolution, and speed. It has the potential to be used for real-time chemical imaging in biology, medicine, and material science.
ANALYTICAL CHEMISTRY
(2022)
Article
Optics
Pablo Castro-Marin, Kerr Johnson, Carl Farrell, Ian A. Davidson, Qiang Fu, Gregory T. Jasion, Natalie Wheeler, Francesco Poletti, David J. Richardson, Derryck T. Reid
Summary: We report the first example of hollow-core fiber-delivered heterodyne spectroscopy in the 3.1-3.8 μm wavelength range, utilizing the short-term phase stability between consecutive pulses from a free-running optical parametric oscillator frequency comb. This technique allows spectroscopic analysis of a sample located at the distal end of a fiber, while suppressing interfering features and achieving high quality transmission. It provides a promising route for implementing multi-species spectroscopic monitoring in remote or hostile environments.
Article
Multidisciplinary Sciences
Angelos Xomalis, Xuezhi Zheng, Rohit Chikkaraddy, Zsuzsanna Koczor-Benda, Ermanno Miele, Edina Rosta, Guy A. E. Vandenbosch, Alejandro Martinez, Jeremy J. Baumberg
Summary: Optomechanical interactions enable coherent interconversion of signals between optical and mechanical domains. Extreme light-matter coupling at nanoscale mode volumes allows single mid-infrared (MIR) photon sensitivity. This study demonstrates frequency upconversion by utilizing infrared absorption and Raman activity of molecular vibrations in plasmonic nanocavities, showing potential for low-cost and large-scale infrared detectors and spectroscopic techniques.
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
Sergey Vasilyev, Andrey Muraviev, Dmitrii Konnov, Mike Mirov, Victor Smolski, Igor Moskalev, Sergey Mirov, Konstantin Vodopyanov
Summary: By using sub-3-cycle pulses from mode-locked Cr:ZnS lasers, high-resolution dual-frequency-comb spectroscopy in the long-wave infrared range was achieved. Highly coherent broadband frequency combs in the range of 6.6-11.4 μm were generated through intrapulse difference frequency generation in zinc germanium phosphide crystals. Metrology grade molecular spectra of N2O and CH3OH were obtained by acquiring 240,000 comb-mode-resolved data points at a fast speed of up to 0.1 s per spectrum, with low intensity and phase noise of the LWIR combs and high downconversion efficiency.
Article
Optics
Tecla Gabbrielli, Giacomo Insero, Michele De Regis, Nicola Corrias, Iacopo Galli, Davide Mazzotti, Paolo Bartolini, Jeong Hyun Huh, Carsten Cleff, Alexander Kastner, Ronald Holzwarth, Simone Borri, Luigi Consolino, Paolo De Natale, Francesco Cappelli
Summary: This study presents a comprehensive approach for characterizing a mid-infrared frequency comb, including pulse width measurement and frequency narrowing. The results show that this approach can effectively compress the pulses and narrow the frequencies of the modes to low values.
Article
Optics
Nazanin Hoghooghi, Sida Xing, Peter Chang, Daniel Lesko, Alexander Lind, Greg Rieker, Scott Diddams
Summary: Mid-infrared (MIR) spectrometers are essential for studying molecular fingerprinting and hyper-spectral imaging. However, current GHz MIR dual-comb absorption spectrometers lack the ability to combine high speed, high spectral resolution, and broad optical bandwidth. This study introduces a broadband MIR frequency comb laser platform that overcomes these limitations, enabling accurate characterization of complex, transient events in chemistry, combustion, and microscopy.
LIGHT-SCIENCE & APPLICATIONS
(2022)
Article
Optics
Muriel Lepere, Olivier Browet, Jean Clement, Bastien Vispoel, Pitt Allmendinger, Jakob Hayden, Florian Eigenmann, Andreas Hugi, Markus Mangold
Summary: To meet the challenges of high-resolution molecular spectroscopy, increasingly sophisticated spectroscopic techniques were developed. The recent development of dual-comb spectroscopy at high-resolution makes this technique a powerful tool for gas phase studies. This study reports on the use and characterization of the IRis-F1, a tabletop mid-infrared dual-comb spectrometer, in the newly developed step-sweep mode.
JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER
(2022)
Article
Optics
Fabrizio R. Giorgetta, Jeff Peischl, Daniel I. Herman, Gabriel Ycas, Ian Coddington, Nathan R. Newbury, Kevin C. Cossel
Summary: Open-path dual-comb spectroscopy has been extended to the mid-infrared 5 µm atmospheric window, enabling high precision measurements of multispecies atmospheric gas concentrations, including primary greenhouse gases and criteria air pollutants. The retrieved ratios of excess CO versus CO2 and N2O versus CO2 show variations and discrepancies with previous studies and emission inventories.
LASER & PHOTONICS REVIEWS
(2021)
Article
Chemistry, Multidisciplinary
Ziheng Wei, Xinyi Ren, Ming Yan, Hulie Zeng
Summary: Analytical chemistry is crucial in molecular analysis, and dual-comb spectroscopy has been widely applied in analytical chemistry due to its high resolution and sensitivity.
CHINESE CHEMICAL LETTERS
(2023)
Article
Nanoscience & Nanotechnology
Lukasz A. Sterczewski, Tzu-Ling Chen, Douglas C. Ober, Charles R. Markus, Chadwick L. Canedy, Igor Vurgaftman, Clifford Frez, Jerry R. Meyer, Mitchio Okumura, Mahmood Bagheri
Summary: Chip-scale optical frequency combs have the potential to be used in broadband spectroscopy and chemical sensing in various fields. By using the Vernier technique, a compact cavity-enhanced chemical sensing system can be realized. The experimental results demonstrate the ability to detect the release of different substances with high resolution and fast response.
Article
Optics
S. L. Camenzind, D. Koenen, B. Willenberg, J. Pupeikis, C. R. Phillips, U. Keller
Summary: Pulse trains emitted from dual-comb systems with low relative timing jitter can be measured using an optical heterodyne detection approach. A new laser with precise timing and low noise has been characterized using this technique.
Article
Physics, Applied
Martin Franckie, Mathieu Bertrand, Jerome Faist
Summary: This article introduces a method for calculating the linewidth enhancement factor (LEF) in a semiconductor laser, which combines a nonequilibrium Green's function model and simulates the material response to the fluctuation of optical intensity. It can consider all relevant electronic effects and predicts the LEF of a quantum cascade laser to be in the range of 0.1-1. Many-body effects, off-resonant transitions, dispersive gain, counter-rotating terms, intensity-dependent transition energy, and precise subband distributions all significantly contribute to the LEF and are important for accurate simulations.
APPLIED PHYSICS LETTERS
(2023)
Article
Chemistry, Analytical
Akshay Nataraj, Bela Tuzson, Michele Gianella, Ivan Prokhorov, Gang Li, Volker Ebert, Jerome Faist, Lukas Emmenegger
Summary: This study presents a direct and nondestructive analytical technique using quantum cascade laser absorption spectroscopy to quantify the isotopic distribution of propane at different positions. Spectral information of propane isotopomers was obtained using a high-resolution Fourier-transform infrared (FTIR) spectrometer, and suitable mid-infrared regions were selected for accurate measurement. Precision measurements of isotopically substituted non-methane hydrocarbons were achieved for the first time using laser absorption spectroscopy.
ANALYTICAL CHEMISTRY
(2023)
Article
Physics, Applied
E. Onder, D. O. Winge, M. Franckie, A. Forrer, U. Senica, G. Scalari, A. Wacker
Summary: The broadening of the emission spectrum in a terahertz device caused by electric field-domain oscillations in quantum cascade lasers with electrical instabilities is investigated through detailed simulations. The effects of electrical injection conditions and external capacitances on light pulsation are explained. Experimental data confirm that oscillation frequencies are not significantly affected by circuit conditions, while a large external capacitance leads to stabilization of the circuit and non-observable oscillations.
JOURNAL OF APPLIED PHYSICS
(2023)
Article
Optics
Philipp Taeschler, Andres Forrer, Mathieu Bertrand, Filippos Kapsalidis, Mattias Beck, Jerome Faist
Summary: In recent years, there has been significant interest in optical frequency combs with frequency modulated output. This study demonstrates an asynchronous optical sampling technique that operates directly in the time domain. By using a mid-infrared quantum cascade laser frequency comb, they were able to measure both the instantaneous intensity and optical frequency of the comb. The results show a quasi-constant intensity output and a close to linear frequency chirp, consistent with phase-resolved spectral measurements. In contrast to previous works, stable phase-locking is achieved with positive intracavity dispersion, leading to an inversion of the observed frequency modulation.
LASER & PHOTONICS REVIEWS
(2023)
Article
Optics
G. Torrioli, A. Forrer, M. Beck, P. Carelli, F. Chiarello, J. Faist, A. Gaggero, E. Giovine, F. Martini, U. Senica, R. Leoni, G. Scalari, S. Cibella
Summary: We investigate the performance of a hot-electron bolometer (HEB) operating at THz frequencies by employing superconducting niobium nitride films. We present the voltage response of the detector, measured with different THz sources, over a wide electrical detection bandwidth. Our results reveal that the impulse response of the fully packaged HEB at 7.5 K exhibits a 3 dB cutoff at around 2 GHz. Notably, the detection capability is still observed above 30 GHz in a heterodyne beating experiment utilizing a THz quantum cascade laser frequency comb. Additionally, we evaluate the HEB sensitivity and measure an optical noise equivalent power (NEP) of 0.8 pW/√Hz at 1 MHz.
Article
Physics, Applied
Sergej Markmann, David Stark, Matthew Singleton, Mattias Beck, Giacomo Scalari
Summary: In this work, we measure the electric field of a free-running terahertz QCL frequency comb using electro-optic sampling and computational phase correction. This method is important for characterizing the time-resolved emission of low-power laser and investigating phase-compensated emission for broadband comb operation.
PHYSICAL REVIEW APPLIED
(2023)
Article
Optics
Philipp Taschler, Lucius Miller, Filippos Kapsalidis, Mattias Beck, Jerome Faist
Summary: By leveraging the picosecond carrier dynamics observed in quantum cascade lasers (QCLs), we have successfully generated 33 ps optical pulses with watt-level peak power using short electrical excitations. Optical injection seeding ensured lasing on a single resonator mode, and the resulting pulses were characterized in both time and frequency domains. These results open new pathways for the generation of highly tunable, high power mid-infrared pulses from a monolithic source.
Article
Multidisciplinary Sciences
Paolo Micheletti, Urban Senica, Andres Forrer, Sara Cibella, Guido Torrioli, Martin Frankie, Mattias Beck, Giacomo Scalari, J'rome Faist
Summary: Quantum cascade lasers (QCLs) offer an intriguing opportunity for generating on-chip optical dissipative Kerr solitons (DKS). Recent observations of DKS in mid-infrared ring QCLs have paved the way for achieving DKS at longer wavelengths. Terahertz ring QCLs with anomalous dispersion were realized using a waveguide planarization technology platform. A concentric coupled waveguide approach was implemented for dispersion compensation, while a passive broadband bullseye antenna improved power extraction and far field. The presence of solitons was confirmed through hysteric behavior, phase difference measurements, and intensity time profile reconstruction, which matched well with numerical simulations based on the Complex Ginzburg-Landau Equation (CGLE).
Article
Engineering, Electrical & Electronic
Tudor Olariu, Mattias Beck, Jerome Faist
Summary: We present a systematic study of the optical design, fabrication, and characterization of quantum cascade laser devices with a frequency around 4.7 THz. The measured devices exhibit consistent spectral performance, with approximately 75% of them having their emission frequency within a 6 GHz band relative to their nominal value. Additionally, we explain how processing variability is exploited to shift the emission frequency post-process and post-measurement.
IEEE JOURNAL OF QUANTUM ELECTRONICS
(2023)
Article
Optics
Urban Senica, Alexander Dikopoltsev, Andres Forrer, Sara Cibella, Guido Torrioli, Mattias Beck, Jerome Faist, Giacomo Scalari
Summary: This study demonstrates the generation of self-starting frequency-modulated combs by enhancing the gain saturation dynamics and nonlinearities through spatial modulation in semiconductor lasers. Using terahertz quantum cascade lasers and taking advantage of spatial confinement, pure frequency-modulated combs with flat intensity spectra and clear linear frequency chirps can be generated.
LASER & PHOTONICS REVIEWS
(2023)
Article
Optics
Kenichi N. N. Komagata, Alexandre Parriaux, Mathieu Bertrand, Johannes Hillbrand, Mattias Beck, Valentin J. J. Wittwer, Jerome Faist, Thomas Sudmeyer
Summary: We use a low power near-infrared laser as an optical actuator to control a mid-infrared frequency comb. By controlling the current and intensity of the lasers, we achieve tight phase lock and low phase noise. We also show that the quantum cascade laser can act as a fast near-infrared light detector and injection locking can be achieved through modulation of the near-infrared light.