1
|
Bauer CP, Bejm ZA, Bollier MK, Pupeikis J, Willenberg B, Keller U, Phillips CR. High-sensitivity dual-comb and cross-comb spectroscopy across the infrared using a widely tunable and free-running optical parametric oscillator. Nat Commun 2024; 15:7211. [PMID: 39174545 PMCID: PMC11341905 DOI: 10.1038/s41467-024-51392-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2023] [Accepted: 08/05/2024] [Indexed: 08/24/2024] Open
Abstract
Dual-comb spectroscopy (DCS) enables high-resolution measurements at high speeds without the trade-off between resolution and update rate inherent to mechanical delay scanning. However, high complexity and limited sensitivity remain significant challenges for DCS systems. We address these via a wavelength-tunable dual-comb optical parametric oscillator (OPO) combined with an up-conversion detection method. The OPO is tunable from 1300-1670 nm (signal) and 2700-5000 nm (idler). Spatial multiplexing in both the laser and OPO cavities creates a near-common path arrangement, enabling comb-line-resolved measurements in free-running operation. The narrow instantaneous bandwidth results in high power per comb-line up to 160 μW in the mid-infrared. Through intra-cavity up-conversion based on cross-comb spectroscopy, we leverage these power levels while overcoming the sensitivity limitations of direct mid-infrared detection. This approach yields a high signal-to-noise ratio (50.2 dB Hz1/2) and high dual-comb figure of merit (3.5 × 108 Hz1/2). This scheme enabled detecting ambient methane over a 3-meter path length in millisecond time scale.
Collapse
Affiliation(s)
- Carolin P Bauer
- Department of Physics, Institute for Quantum Electronics, ETH Zurich, Zurich, Switzerland.
| | - Zofia A Bejm
- Department of Physics, Institute for Quantum Electronics, ETH Zurich, Zurich, Switzerland
| | - Michelle K Bollier
- Department of Physics, Institute for Quantum Electronics, ETH Zurich, Zurich, Switzerland
| | - Justinas Pupeikis
- Department of Physics, Institute for Quantum Electronics, ETH Zurich, Zurich, Switzerland
| | - Benjamin Willenberg
- Department of Physics, Institute for Quantum Electronics, ETH Zurich, Zurich, Switzerland
| | - Ursula Keller
- Department of Physics, Institute for Quantum Electronics, ETH Zurich, Zurich, Switzerland
| | - Christopher R Phillips
- Department of Physics, Institute for Quantum Electronics, ETH Zurich, Zurich, Switzerland
| |
Collapse
|
2
|
Eissa T, Leonardo C, Kepesidis KV, Fleischmann F, Linkohr B, Meyer D, Zoka V, Huber M, Voronina L, Richter L, Peters A, Žigman M. Plasma infrared fingerprinting with machine learning enables single-measurement multi-phenotype health screening. Cell Rep Med 2024; 5:101625. [PMID: 38944038 PMCID: PMC11293328 DOI: 10.1016/j.xcrm.2024.101625] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2023] [Revised: 04/19/2024] [Accepted: 06/07/2024] [Indexed: 07/01/2024]
Abstract
Infrared spectroscopy is a powerful technique for probing the molecular profiles of complex biofluids, offering a promising avenue for high-throughput in vitro diagnostics. While several studies showcased its potential in detecting health conditions, a large-scale analysis of a naturally heterogeneous potential patient population has not been attempted. Using a population-based cohort, here we analyze 5,184 blood plasma samples from 3,169 individuals using Fourier transform infrared (FTIR) spectroscopy. Applying a multi-task classification to distinguish between dyslipidemia, hypertension, prediabetes, type 2 diabetes, and healthy states, we find that the approach can accurately single out healthy individuals and characterize chronic multimorbid states. We further identify the capacity to forecast the development of metabolic syndrome years in advance of onset. Dataset-independent testing confirms the robustness of infrared signatures against variations in sample handling, storage time, and measurement regimes. This study provides the framework that establishes infrared molecular fingerprinting as an efficient modality for populational health diagnostics.
Collapse
Affiliation(s)
- Tarek Eissa
- Department of Laser Physics, Ludwig Maximilian University of Munich (LMU), Garching, Germany; Laboratory for Attosecond Physics, Max Planck Institute of Quantum Optics (MPQ), Garching, Germany; School of Computation, Information and Technology, Technical University of Munich (TUM), Garching, Germany.
| | - Cristina Leonardo
- Department of Laser Physics, Ludwig Maximilian University of Munich (LMU), Garching, Germany
| | - Kosmas V Kepesidis
- Department of Laser Physics, Ludwig Maximilian University of Munich (LMU), Garching, Germany; Laboratory for Attosecond Physics, Max Planck Institute of Quantum Optics (MPQ), Garching, Germany; Center for Molecular Fingerprinting (CMF), Budapest, Hungary
| | - Frank Fleischmann
- Department of Laser Physics, Ludwig Maximilian University of Munich (LMU), Garching, Germany; Laboratory for Attosecond Physics, Max Planck Institute of Quantum Optics (MPQ), Garching, Germany
| | - Birgit Linkohr
- Institute of Epidemiology, Helmholtz Zentrum München, Neuherberg, Germany
| | - Daniel Meyer
- Laboratory for Attosecond Physics, Max Planck Institute of Quantum Optics (MPQ), Garching, Germany; Center for Molecular Fingerprinting (CMF), Budapest, Hungary
| | - Viola Zoka
- Department of Laser Physics, Ludwig Maximilian University of Munich (LMU), Garching, Germany; Center for Molecular Fingerprinting (CMF), Budapest, Hungary
| | - Marinus Huber
- Department of Laser Physics, Ludwig Maximilian University of Munich (LMU), Garching, Germany; Laboratory for Attosecond Physics, Max Planck Institute of Quantum Optics (MPQ), Garching, Germany
| | - Liudmila Voronina
- Department of Laser Physics, Ludwig Maximilian University of Munich (LMU), Garching, Germany
| | - Lothar Richter
- School of Computation, Information and Technology, Technical University of Munich (TUM), Garching, Germany
| | - Annette Peters
- Institute of Epidemiology, Helmholtz Zentrum München, Neuherberg, Germany; School of Public Health, Institute for Medical Information Processing, Biometry, and Epidemiology, Pettenkofer, Ludwig Maximilian University of Munich (LMU), Munich, Germany; German Center for Diabetes Research (DZD), Neuherberg, Germany; German Centre for Cardiovascular Research (DZHK), Partner Site Munich, Munich, Germany
| | - Mihaela Žigman
- Department of Laser Physics, Ludwig Maximilian University of Munich (LMU), Garching, Germany; Laboratory for Attosecond Physics, Max Planck Institute of Quantum Optics (MPQ), Garching, Germany.
| |
Collapse
|
3
|
Sadiek I, Fleisher AJ, Hayden J, Huang X, Hugi A, Engeln R, Lang N, van Helden JPH. Dual-comb spectroscopy of ammonia formation in non-thermal plasmas. Commun Chem 2024; 7:110. [PMID: 38741005 DOI: 10.1038/s42004-024-01190-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2024] [Accepted: 04/26/2024] [Indexed: 05/16/2024] Open
Abstract
Plasma-activated chemical transformations promise the efficient synthesis of salient chemical products. However, the reaction pathways that lead to desirable products are often unknown, and key quantum-state-resolved information regarding the involved molecular species is lacking. Here we use quantum cascade laser dual-comb spectroscopy (QCL-DCS) to probe plasma-activated NH3 generation with rotational and vibrational state resolution, quantifying state-specific number densities via broadband spectral analysis. The measurements reveal unique translational, rotational and vibrational temperatures for NH3 products, indicative of a highly reactive, non-thermal environment. Ultimately, we postulate on the energy transfer mechanisms that explain trends in temperatures and number densities observed for NH3 generated in low-pressure nitrogen-hydrogen (N2-H2) plasmas.
Collapse
Affiliation(s)
- Ibrahim Sadiek
- Leibniz Institute for Plasma Science and Technology (INP), 17489, Greifswald, Germany.
| | - Adam J Fleisher
- Material Measurement Laboratory, National Institute of Standards and Technology, 20899, Gaithersburg, MD, USA.
| | | | | | | | - Richard Engeln
- Plasma Physics Research, ASML Veldhoven, 5504, DR, Veldhoven, The Netherlands
- Department of Applied Physics, Eindhoven University of Technology, 5600, MB, Eindhoven, The Netherlands
| | - Norbert Lang
- Leibniz Institute for Plasma Science and Technology (INP), 17489, Greifswald, Germany
| | | |
Collapse
|
4
|
Moretti L, Walsh M, Abualsaud N, Gatti D, Lamperti M, Genest J, Farooq A, Marangoni M. Fast rate dual-comb spectrometer in the water-transparent 7.5-11.5 µm region. OPTICS LETTERS 2024; 49:1844-1847. [PMID: 38560879 DOI: 10.1364/ol.515199] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/07/2023] [Accepted: 02/23/2024] [Indexed: 04/04/2024]
Abstract
We introduce a dual-comb spectrometer based on erbium fiber oscillators at 250 MHz that operates in the 7.5-11.5 µm spectral range over optical bandwidths up to 9 THz with a multi-kHz acquisition rate. Over an observation bandwidth of 0.8 THz, the signal-to-noise ratio per spectral point reaches 168 Hz0.5 at an acquisition rate of 26 kHz, which allows the investigation of transient processes in the gas phase at high temporal resolution. The system also represents an attractive solution for multi-species atmospheric gas detection in open paths due to the water transparency of the spectral window, the use of thermo-electrically cooled detectors, and the out-of-loop phase correction of the interferograms.
Collapse
|
5
|
Marschick G, Pelini J, Gabbrielli T, Cappelli F, Weih R, Knötig H, Koeth J, Höfling S, De Natale P, Strasser G, Borri S, Hinkov B. Mid-infrared Ring Interband Cascade Laser: Operation at the Standard Quantum Limit. ACS PHOTONICS 2024; 11:395-403. [PMID: 38405392 PMCID: PMC10885206 DOI: 10.1021/acsphotonics.3c01159] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/14/2023] [Revised: 12/26/2023] [Accepted: 12/27/2023] [Indexed: 02/27/2024]
Abstract
Many precision applications in the mid-infrared spectral range have strong constraints based on quantum effects that are expressed in particular noise characteristics. They limit, e.g., sensitivity and resolution of mid-infrared imaging and spectroscopic systems as well as the bit-error rate in optical free-space communication. Interband cascade lasers (ICLs) are a class of mid-infrared lasers exploiting interband transitions in type-II band alignment geometry. They are currently gaining significant importance for mid-infrared applications from < 3 to > 6 μm wavelength, enabled by novel types of high-performance ICLs such as ring-cavity devices. Their noise behavior is an important feature that still needs to be thoroughly analyzed, including its potential reduction with respect to the shot-noise limit. In this work, we provide a comprehensive characterization of λ = 3.8 μm-emitting, continuous-wave ring ICLs operating at room temperature. It is based on an in-depth study of their main physical intensity noise features such as their bias-dependent intensity noise power spectral density and relative intensity noise. We obtained shot-noise-limited statistics for Fourier frequencies above 100 kHz. This is an important result for precision applications, e.g., interferometry or advanced spectroscopy, which benefit from exploiting the advantage of using such a shot-noise-limited source, enhancing the setup sensitivity. Moreover, it is an important feature for novel quantum optics schemes, including testing specific light states below the shot-noise level, such as squeezed states.
Collapse
Affiliation(s)
- Georg Marschick
- TU
Wien—Institute of Solid State Electronics & Center for
Micro- and Nanostructures, Gußhausstraße 25-25a, Vienna 1040, Austria
| | - Jacopo Pelini
- University
of Naples Federico II, Corso Umberto I 40, Napoli 80138, Italy
- CNR-INO—Istituto
Nazionale di Ottica, Largo Fermi, 6, Firenze, FI 50125, Italy
| | - Tecla Gabbrielli
- CNR-INO—Istituto
Nazionale di Ottica, Via Carrara, 1, Sesto Fiorentino, Florence 50019, Italy
- LENS—European
Laboratory for Non-Linear Spectroscopy, Via Carrara, 1, Sesto Fiorentino, Florence 50019, Italy
| | - Francesco Cappelli
- CNR-INO—Istituto
Nazionale di Ottica, Via Carrara, 1, Sesto Fiorentino, Florence 50019, Italy
- LENS—European
Laboratory for Non-Linear Spectroscopy, Via Carrara, 1, Sesto Fiorentino, Florence 50019, Italy
| | - Robert Weih
- nanoplus
Nanosystems and Technologies GmbH, Oberer Kirschberg 4, Gerbrunn 97218, Germany
| | - Hedwig Knötig
- TU
Wien—Institute of Solid State Electronics & Center for
Micro- and Nanostructures, Gußhausstraße 25-25a, Vienna 1040, Austria
| | - Johannes Koeth
- nanoplus
Nanosystems and Technologies GmbH, Oberer Kirschberg 4, Gerbrunn 97218, Germany
| | - Sven Höfling
- Julius-Maximilians-Universität
Würzburg—Physikalisches Institut, Lehrstuhl für Technische Physik, Am Hubland, Würzburg 97074, Germany
| | - Paolo De Natale
- CNR-INO—Istituto
Nazionale di Ottica, Largo Fermi, 6, Firenze, FI 50125, Italy
- CNR-INO—Istituto
Nazionale di Ottica, Via Carrara, 1, Sesto Fiorentino, Florence 50019, Italy
- LENS—European
Laboratory for Non-Linear Spectroscopy, Via Carrara, 1, Sesto Fiorentino, Florence 50019, Italy
- INFN—Istituto
Nazionale di Fisica Nucleare, Via Sansone, 1, Sesto Fiorentino, Florence 50019, Italy
| | - Gottfried Strasser
- TU
Wien—Institute of Solid State Electronics & Center for
Micro- and Nanostructures, Gußhausstraße 25-25a, Vienna 1040, Austria
| | - Simone Borri
- CNR-INO—Istituto
Nazionale di Ottica, Via Carrara, 1, Sesto Fiorentino, Florence 50019, Italy
- LENS—European
Laboratory for Non-Linear Spectroscopy, Via Carrara, 1, Sesto Fiorentino, Florence 50019, Italy
- INFN—Istituto
Nazionale di Fisica Nucleare, Via Sansone, 1, Sesto Fiorentino, Florence 50019, Italy
| | - Borislav Hinkov
- TU
Wien—Institute of Solid State Electronics & Center for
Micro- and Nanostructures, Gußhausstraße 25-25a, Vienna 1040, Austria
| |
Collapse
|
6
|
Eber A, Fürst L, Siegrist F, Kirchner A, Tschofenig B, di Vora R, Speletz A, Bernhardt B. Coherent field sensing of nitrogen dioxide. OPTICS EXPRESS 2024; 32:6575-6586. [PMID: 38439357 DOI: 10.1364/oe.513523] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2023] [Accepted: 01/19/2024] [Indexed: 03/06/2024]
Abstract
We introduce a portable dual-comb spectrometer operating in the visible spectral region for atmospheric monitoring of NO2, a pollution gas of major importance. Dual-comb spectroscopy, combining key advantages of fast, broadband and accurate measurements, has been established in the infrared as a method for the investigation of atmospheric gases with kilometer-scale absorption path lengths. With the presented dual-comb spectrometer centered at 517 nm, we make use of the strong absorption cross section of NO2 in this spectral region. In combination with a multi-pass approach through the atmosphere, we achieve an interaction path length of almost a kilometer while achieving both advanced spatial resolution (90 m) and a detection sensitivity of 5 ppb. The demonstrated temporal resolution of one minute outperforms the standard chemiluminescence-based NO2 detector that is commercially available and used in this experiment, by a factor of three.
Collapse
|
7
|
Huang B, Kosan N, Wysocki G. Controlled generation of harmonic states in mid-infrared quantum cascade laser frequency combs by external cavity optical feedback. OPTICS EXPRESS 2024; 32:1966-1978. [PMID: 38297737 DOI: 10.1364/oe.510431] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/21/2023] [Accepted: 11/21/2023] [Indexed: 02/02/2024]
Abstract
We demonstrate the implementation of external cavity optical feedback to improve coherence and promote generation of harmonic states by a mid-infrared quantum cascade laser frequency comb. In particular, we present a Vernier-like scheme to realize harmonic comb states that increase the repetition rate of the comb by a factor of up to 6 and broaden spectral coverages from 46 cm-1 to 92 cm-1. Intermode beatnote and dual comb characterization indicate that the coherence of the comb has greatly improved for sub-optimal devices when the comb is operated in these harmonic states. This approach to control the generation of harmonic states and improve comb performance can be readily incorporated to various sensing systems and has great potential in spectroscopic measurements that require high repetition rates and/or broad optical bandwidth.
Collapse
|
8
|
Wang Z, Nie Q, Sun H, Wang Q, Borri S, De Natale P, Ren W. Cavity-enhanced photoacoustic dual-comb spectroscopy. LIGHT, SCIENCE & APPLICATIONS 2024; 13:11. [PMID: 38177145 PMCID: PMC10767139 DOI: 10.1038/s41377-023-01353-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2023] [Revised: 12/01/2023] [Accepted: 12/07/2023] [Indexed: 01/06/2024]
Abstract
Photoacoustic dual-comb spectroscopy (DCS), converting spectral information in the optical frequency domain to the audio frequency domain via multi-heterodyne beating, enables background-free spectral measurements with high resolution and broad bandwidth. However, the detection sensitivity remains limited due to the low power of individual comb lines and the lack of broadband acoustic resonators. Here, we develop cavity-enhanced photoacoustic DCS, which overcomes these limitations by using a high-finesse optical cavity for the power amplification of dual-frequency combs and a broadband acoustic resonator with a flat-top frequency response. We demonstrate high-resolution spectroscopic measurements of trace amounts of C2H2, NH3 and CO in the entire telecommunications C-band. The method shows a minimum detection limit of 0.6 ppb C2H2 at the measurement time of 100 s, corresponding to the noise equivalent absorption coefficient of 7 × 10-10 cm-1. The proposed cavity-enhanced photoacoustic DCS may open new avenues for ultrasensitive, high-resolution, and multi-species gas detection with widespread applications.
Collapse
Affiliation(s)
- Zhen Wang
- Department of Mechanical and Automation Engineering, The Chinese University of Hong Kong, New Territories, Hong Kong SAR, China.
| | - Qinxue Nie
- Department of Mechanical and Automation Engineering, The Chinese University of Hong Kong, New Territories, Hong Kong SAR, China
| | - Haojia Sun
- Department of Mechanical and Automation Engineering, The Chinese University of Hong Kong, New Territories, Hong Kong SAR, China
| | - Qiang Wang
- State Key Laboratory of Applied Optics, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, 130033, Changchun, China.
| | - Simone Borri
- CNR-INO-Istituto Nazionale di Ottica, and LENS-European Laboratory for Nonlinear Spectroscopy, 50019, Sesto Fiorentino, Italy
| | - Paolo De Natale
- CNR-INO-Istituto Nazionale di Ottica, and LENS-European Laboratory for Nonlinear Spectroscopy, 50019, Sesto Fiorentino, Italy
| | - Wei Ren
- Department of Mechanical and Automation Engineering, The Chinese University of Hong Kong, New Territories, Hong Kong SAR, China.
| |
Collapse
|
9
|
Lang Z, Qiao S, Liang T, He Y, Qi L, Ma Y. Dual-frequency modulated heterodyne quartz-enhanced photoacoustic spectroscopy. OPTICS EXPRESS 2024; 32:379-386. [PMID: 38175068 DOI: 10.1364/oe.506861] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2023] [Accepted: 11/02/2023] [Indexed: 01/05/2024]
Abstract
A novel dual-frequency modulated heterodyne quartz-enhanced photoacoustic spectroscopy (DFH-QEPAS) was demonstrated for what we believe to be the first time in this study. In traditional H-QEPAS, the frequency of modulated sinusoidal wave has a frequency difference (Δf) with the resonance frequency (f0) of a quartz tuning fork (QTF). Owing to the resonance characteristic of QTF, it cannot excite QTF to the strongest response. To achieve a stronger response, a sinusoidal wave with a frequency of f0 was added to the modulation wave to compose a dual-frequency modulation. Acetylene (C2H2) was chosen as the target gas to verify the sensor performance. The proposed DFH-QEPAS improved 4.05 times of signal-to-noise ratio (SNR) compared with the traditional H-QEPAS in the same environmental conditions.
Collapse
|
10
|
Opačak N, Kazakov D, Columbo LL, Beiser M, Letsou TP, Pilat F, Brambilla M, Prati F, Piccardo M, Capasso F, Schwarz B. Nozaki-Bekki solitons in semiconductor lasers. Nature 2024; 625:685-690. [PMID: 38267681 DOI: 10.1038/s41586-023-06915-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2023] [Accepted: 11/29/2023] [Indexed: 01/26/2024]
Abstract
Optical frequency-comb sources, which emit perfectly periodic and coherent waveforms of light1, have recently rapidly progressed towards chip-scale integrated solutions. Among them, two classes are particularly significant-semiconductor Fabry-Perót lasers2-6 and passive ring Kerr microresonators7-9. Here we merge the two technologies in a ring semiconductor laser10,11 and demonstrate a paradigm for the formation of free-running solitons, called Nozaki-Bekki solitons. These dissipative waveforms emerge in a family of travelling localized dark pulses, known within the complex Ginzburg-Landau equation12-14. We show that Nozaki-Bekki solitons are structurally stable in a ring laser and form spontaneously with tuning of the laser bias, eliminating the need for an external optical pump. By combining conclusive experimental findings and a complementary elaborate theoretical model, we reveal the salient characteristics of these solitons and provide guidelines for their generation. Beyond the fundamental soliton circulating inside the ring laser, we demonstrate multisoliton states as well, verifying their localized nature and offering an insight into formation of soliton crystals15. Our results consolidate a monolithic electrically driven platform for direct soliton generation and open the door for a research field at the junction of laser multimode dynamics and Kerr parametric processes.
Collapse
Affiliation(s)
- Nikola Opačak
- Institute of Solid State Electronics, TU Wien, Vienna, Austria.
- Harvard John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA, USA.
| | - Dmitry Kazakov
- Harvard John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA, USA
| | - Lorenzo L Columbo
- Dipartimento di Elettronica e Telecomunicazioni, Politecnico di Torino, Turin, Italy
| | | | - Theodore P Letsou
- Harvard John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA, USA
- Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Florian Pilat
- Institute of Solid State Electronics, TU Wien, Vienna, Austria
| | - Massimo Brambilla
- Dipartimento di Fisica Interateneo and CNR-IFN, Università e Politecnico di Bari, Bari, Italy
| | - Franco Prati
- Dipartimento di Scienza e Alta Tecnologia, Università dell'Insubria, Como, Italy
| | - Marco Piccardo
- Harvard John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA, USA
- Department of Physics, Instituto Superior Técnico, Universidade de Lisboa, Lisbon, Portugal
- Instituto de Engenharia de Sistemas e Computadores - Microsistemas e Nanotecnologias (INESC MN), Lisbon, Portugal
| | - Federico Capasso
- Harvard John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA, USA
| | - Benedikt Schwarz
- Institute of Solid State Electronics, TU Wien, Vienna, Austria.
- Harvard John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA, USA.
| |
Collapse
|
11
|
Gabbrielli T, Insero G, De Regis M, Corrias N, Galli I, Mazzotti D, Bartolini P, Hyun Huh J, Cleff C, Kastner A, Holzwarth R, Borri S, Consolino L, De Natale P, Cappelli F. Time/frequency-domain characterization of a mid-IR DFG frequency comb via two-photon and heterodyne detection. OPTICS EXPRESS 2023; 31:35330-35342. [PMID: 37859267 DOI: 10.1364/oe.493321] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/17/2023] [Accepted: 06/20/2023] [Indexed: 10/21/2023]
Abstract
Mid-infrared frequency combs are nowadays well-appreciated sources for spectroscopy and frequency metrology. Here, a comprehensive approach for characterizing a difference-frequency-generated mid-infrared frequency comb (DFG-comb) both in the time and in the frequency domain is presented. An autocorrelation scheme exploiting mid-infrared two-photon detection is used for characterizing the pulse width and to verify the optimal compression of the generated pulses reaching a pulse duration (FWHM) as low as 196 fs. A second scheme based on mid-infrared heterodyne detection employing two independent narrow-linewidth quantum cascade lasers (QCLs) is used for frequency-narrowing the modes of the DFG-comb down to 9.4 kHz on a 5-ms timescale.
Collapse
|
12
|
Smołka T, Rygała M, Hilska J, Puustinen J, Koivusalo E, Guina M, Motyka M. Influence of the Bismuth Content on the Optical Properties and Photoluminescence Decay Time in GaSbBi Films. ACS OMEGA 2023; 8:36355-36360. [PMID: 37810694 PMCID: PMC10552505 DOI: 10.1021/acsomega.3c05046] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/13/2023] [Accepted: 09/08/2023] [Indexed: 10/10/2023]
Abstract
We report the optical properties of GaSbBi layers grown on GaSb (100) substrates with different bismuth contents of 5.8 and 8.0% Bi. Fourier-transform photoluminescence spectra were determined to identify the band gaps of the studied materials. Further temperature- and power-dependent photoluminescence measurements indicated the presence of localized states connected to bismuth clustering. Finally, time-resolved photoluminescence measurements based on single-photon counting allowed the determination of characteristic photoluminescence decay time constants. Because of the increasing bismuth content and clustering effects, an increase in the time constant was observed.
Collapse
Affiliation(s)
- Tristan Smołka
- Laboratory
for Optical Spectroscopy of Nanostructures, Department of Experimental
Physics, Faculty of Fundamental Problems of Technology, Wrocław University of Science and Technology, Wybrzeże Wyspiańskiego
27, 50-370 Wrocław, Poland
| | - Michał Rygała
- Laboratory
for Optical Spectroscopy of Nanostructures, Department of Experimental
Physics, Faculty of Fundamental Problems of Technology, Wrocław University of Science and Technology, Wybrzeże Wyspiańskiego
27, 50-370 Wrocław, Poland
| | - Joonas Hilska
- Optoelectronics
Research Centre, Physics Unit, Tampere University, Korkeakoulunkatu 3, 33720 Tampere, Finland
| | - Janne Puustinen
- Optoelectronics
Research Centre, Physics Unit, Tampere University, Korkeakoulunkatu 3, 33720 Tampere, Finland
| | - Eero Koivusalo
- Optoelectronics
Research Centre, Physics Unit, Tampere University, Korkeakoulunkatu 3, 33720 Tampere, Finland
| | - Mircea Guina
- Optoelectronics
Research Centre, Physics Unit, Tampere University, Korkeakoulunkatu 3, 33720 Tampere, Finland
| | - Marcin Motyka
- Laboratory
for Optical Spectroscopy of Nanostructures, Department of Experimental
Physics, Faculty of Fundamental Problems of Technology, Wrocław University of Science and Technology, Wybrzeże Wyspiańskiego
27, 50-370 Wrocław, Poland
| |
Collapse
|
13
|
Jin Y, Sun F, Li J, Tan CS, Tan KH, Wicaksono S, Sirtori C, Yoon SF, Wang QJ. Long wavelength mid-infrared multi-gases spectroscopy using tunable single-mode slot waveguide quantum cascade laser. OPTICS EXPRESS 2023; 31:27543-27552. [PMID: 37710827 DOI: 10.1364/oe.495160] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/09/2023] [Accepted: 07/20/2023] [Indexed: 09/16/2023]
Abstract
Single-mode tunable quantum cascade lasers (QCLs) are promising for high-resolution and highly sensitive trace gases sensing across the mid-infrared (MIR) region. We report on the development of a tunable single-mode slot waveguide QCL array in the long wavelength part of the MIR regime (>12 µm). This laser array exhibits a tuning range of around 12 cm-1, from 735.3 to 747.3 cm-1. Using this developed single-mode tunable QCL, we demonstrate individual gas sensing, yielding the detection limit of 940 ppb and 470 ppb for acetylene and o-xylene, respectively. To verify the potential of the developed QCL array in multi-species gas detection, laser absorption measurements of two mixed gases of acetylene and o-xylene were conducted, showing the absorption features of the corresponding gases agree well with the theoretical predictions.
Collapse
|
14
|
Mikulicz M, Rygała M, Smołka T, Janczak M, Badura M, Łozińska A, Wolf A, Emmerling M, Ściana B, Höfling S, Czyszanowski T, Sęk G, Motyka M. Enhancement of quantum cascade laser intersubband transitions via coupling to resonant discrete photonic modes of subwavelength gratings. OPTICS EXPRESS 2023; 31:26898-26909. [PMID: 37710539 DOI: 10.1364/oe.496261] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/23/2023] [Accepted: 07/13/2023] [Indexed: 09/16/2023]
Abstract
We present an optical spectroscopic study of InGaAs/AlInAs active region of quantum cascade lasers grown by low pressure metal organic vapor phase epitaxy combined with subwavelength gratings fabricated by reactive ion etching. Fourier-transformed photoluminescence measurements were used to compare the emission properties of structures before and after processing the gratings. Our results demonstrate a significant increase of the photoluminescence intensity related to intersubband transitions in the mid-infrared, which is attributed to coupling with the grating modes via so called photonic Fano resonances. Our findings demonstrate a promising method for enhancing the emission in optoelectronic devices operating in a broad range of application-relevant infrared.
Collapse
|
15
|
Ghosh S, Eisenstein G. Highly coherent hybrid dual-comb spectrometer. OPTICS EXPRESS 2023; 31:25093-25103. [PMID: 37475322 DOI: 10.1364/oe.496190] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/23/2023] [Accepted: 06/29/2023] [Indexed: 07/22/2023]
Abstract
Dual comb spectroscopy (DCS) is a broadband technique offering high resolution and fast data acquisition. Current state-of-the-art designs are based on a pair of fiber or solid-state lasers, which allow broadband spectroscopy but require a complicated stabilization setup. Semiconductor lasers are tunable, cost-effective, and easily integrable while limited by a narrow bandwidth. This motivates a hybrid design combining the advantages of both systems. However, establishing sufficiently long mutual coherence time remains challenging. This work describes a hybrid dual-comb spectrometer comprising a broadband fiber laser (FC) and an actively mode-locked semiconductor laser (MLL) with a narrow but tunable spectrum. A high mutual coherence time of around 100 seconds has been achieved by injection locking the MLL to a continuous laser (CW), which is locked on a single line of the FC. We have also devised a method to directly stabilize the entire spectrum of FC to a high finesse cavity. This results in a long term stability of 5 × 10-12 at 1 second and 5 × 10-14 at 350 seconds. Additionally, we have addressed the effect of cavity dispersion on the locking quality, which is important for broadband comb lasers.
Collapse
|
16
|
Markmann S, Franckié M, Bertrand M, Shahmohammadi M, Forrer A, Jouy P, Beck M, Faist J, Scalari G. Frequency chirped Fourier-Transform spectroscopy. COMMUNICATIONS PHYSICS 2023; 6:53. [PMID: 38665410 PMCID: PMC11041810 DOI: 10.1038/s42005-023-01157-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/06/2022] [Accepted: 02/24/2023] [Indexed: 04/28/2024]
Abstract
Fast (sub-second) spectroscopy with high spectral resolution is of vital importance for revealing quantum chemistry kinetics of complex chemical and biological reactions. Fourier transform (FT) spectrometers can achieve high spectral resolution and operate at hundreds of ms time scales in rapid-scan mode. However, the linear translation of a scanning mirror imposes stringent time-resolution limitations to these systems, which makes simultaneous high spectral and temporal resolution very difficult. Here, we demonstrate an FT spectrometer whose operational principle is based on continuous rotational motion of the scanning mirror, effectively decoupling the spectral resolution from the temporal one. Furthermore, we show that such rotational FT spectrometer can perform Mid-IR dual-comb spectroscopy with a single comb source, since the Doppler-shifted version of the comb serves as the second comb. In our realization, we combine the advantages of dual-comb and FT spectroscopy using a single quantum cascade laser frequency comb emitting at 8.2 μm as a light source. Our technique does not require any diffractive or dispersive optical elements and hence preserve the Jacquinot's-, Fellgett's-, and Connes'-advantages of FT spectrometers. By integrating mulitple broadband sources, such system could pave the way for applications where high speed, large optical bandwidth, and high spectral resolution are desired.
Collapse
Affiliation(s)
- Sergej Markmann
- Institute for Quantum Electronics, ETH Zürich, Auguste-Piccard-Hof 1, Zürich, 8093 Zürich, Switzerland
| | - Martin Franckié
- Institute for Quantum Electronics, ETH Zürich, Auguste-Piccard-Hof 1, Zürich, 8093 Zürich, Switzerland
| | - Mathieu Bertrand
- Institute for Quantum Electronics, ETH Zürich, Auguste-Piccard-Hof 1, Zürich, 8093 Zürich, Switzerland
| | - Mehran Shahmohammadi
- Institute for Quantum Electronics, ETH Zürich, Auguste-Piccard-Hof 1, Zürich, 8093 Zürich, Switzerland
| | - Andres Forrer
- Institute for Quantum Electronics, ETH Zürich, Auguste-Piccard-Hof 1, Zürich, 8093 Zürich, Switzerland
| | - Pierre Jouy
- Institute for Quantum Electronics, ETH Zürich, Auguste-Piccard-Hof 1, Zürich, 8093 Zürich, Switzerland
| | - Mattias Beck
- Institute for Quantum Electronics, ETH Zürich, Auguste-Piccard-Hof 1, Zürich, 8093 Zürich, Switzerland
| | - Jérôme Faist
- Institute for Quantum Electronics, ETH Zürich, Auguste-Piccard-Hof 1, Zürich, 8093 Zürich, Switzerland
| | - Giacomo Scalari
- Institute for Quantum Electronics, ETH Zürich, Auguste-Piccard-Hof 1, Zürich, 8093 Zürich, Switzerland
| |
Collapse
|
17
|
Ma Y, Gao X, Li W, Liu J, Zhuo N, Yang K, Zhang J, Zhai S, Liu S, Wang L, Liu F. Inserting self-assembled InAs quantum dots into quantum cascade lasers to achieve a broadband free-running frequency comb and effective radio-frequency injection. OPTICS EXPRESS 2023; 31:9729-9738. [PMID: 37157536 DOI: 10.1364/oe.484644] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
We present what we belive to be a new band design in which self-assembled InAs quantum dots (QD) are embedded in InGaAs quantum wells (QW) to fabricate broadband single-core quantum dot cascade lasers (QDCLs) operating as frequency combs. The hybrid active region scheme was exploited to form upper hybrid QW/QD energy states and lower pure QD energy states, which expanded the total laser bandwidth by up to 55 cm-1 due to a broad gain medium provided by the inherent spectral inhomogeneity of self-assembled QDs. The continuous-wave (CW) output power of these devices was as high as 470 mW with optical spectra centered at ∼7 µm, which allowed CW operation at temperatures up to 45 °C . Remarkably, measurement of the intermode beatnote map revealed a clear frequency comb regime extending over a continuous 200 mA current range. Moreover, the modes were self-stabilized with intermode beatnote linewidths of approximately 1.6 kHz. Furthermore, what we believe to be a novel π-shaped electrode design and coplanar waveguide transition way were used for RF signal injection. We found that RF injection modified the laser spectral bandwidth by up to 62 cm-1. The developing characteristics indicate the potential for comb operation based on QDCLs as well as the realization of ultrafast mid-infrared pulse.
Collapse
|
18
|
Hashimoto K, Nakamura T, Kageyama T, Badarla VR, Shimada H, Horisaki R, Ideguchi T. Upconversion time-stretch infrared spectroscopy. LIGHT, SCIENCE & APPLICATIONS 2023; 12:48. [PMID: 36869075 PMCID: PMC9984475 DOI: 10.1038/s41377-023-01096-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/01/2022] [Revised: 01/24/2023] [Accepted: 02/05/2023] [Indexed: 06/18/2023]
Abstract
High-speed measurement confronts the extreme speed limit when the signal becomes comparable to the noise level. In the context of broadband mid-infrared spectroscopy, state-of-the-art ultrafast Fourier-transform infrared spectrometers, in particular dual-comb spectrometers, have improved the measurement rate up to a few MSpectra s-1, which is limited by the signal-to-noise ratio. Time-stretch infrared spectroscopy, an emerging ultrafast frequency-swept mid-infrared spectroscopy technique, has shown a record-high rate of 80 MSpectra s-1 with an intrinsically higher signal-to-noise ratio than Fourier-transform spectroscopy by more than the square-root of the number of spectral elements. However, it can measure no more than ~30 spectral elements with a low resolution of several cm-1. Here, we significantly increase the measurable number of spectral elements to more than 1000 by incorporating a nonlinear upconversion process. The one-to-one mapping of a broadband spectrum from the mid-infrared to the near-infrared telecommunication region enables low-loss time-stretching with a single-mode optical fiber and low-noise signal detection with a high-bandwidth photoreceiver. We demonstrate high-resolution mid-infrared spectroscopy of gas-phase methane molecules with a high resolution of 0.017 cm-1. This unprecedentedly high-speed vibrational spectroscopy technique would satisfy various unmet needs in experimental molecular science, e.g., measuring ultrafast dynamics of irreversible phenomena, statistically analyzing a large amount of heterogeneous spectral data, or taking broadband hyperspectral images at a high frame rate.
Collapse
Affiliation(s)
- Kazuki Hashimoto
- Institute for Photon Science and Technology, The University of Tokyo, Tokyo, 113-0033, Japan
| | - Takuma Nakamura
- Institute for Photon Science and Technology, The University of Tokyo, Tokyo, 113-0033, Japan
| | - Takahiro Kageyama
- Department of Physics, The University of Tokyo, Tokyo, 113-0033, Japan
| | - Venkata Ramaiah Badarla
- Institute for Photon Science and Technology, The University of Tokyo, Tokyo, 113-0033, Japan
| | - Hiroyuki Shimada
- Institute for Photon Science and Technology, The University of Tokyo, Tokyo, 113-0033, Japan
| | - Ryoich Horisaki
- Graduate School of Information Science and Technology, The University of Tokyo, Tokyo, 113-8656, Japan
| | - Takuro Ideguchi
- Institute for Photon Science and Technology, The University of Tokyo, Tokyo, 113-0033, Japan.
- Department of Physics, The University of Tokyo, Tokyo, 113-0033, Japan.
| |
Collapse
|
19
|
Bredács M, Kanatschnig E, Frank A, Oreski G, Pinter G, Gergely S. Identifying active and degraded phenolic antioxidants in aged PE with IR-microscopy. Polym Degrad Stab 2023. [DOI: 10.1016/j.polymdegradstab.2023.110345] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/29/2023]
|
20
|
Liu M, Gray RM, Costa L, Markus CR, Roy A, Marandi A. Mid-infrared cross-comb spectroscopy. Nat Commun 2023; 14:1044. [PMID: 36828826 PMCID: PMC9957991 DOI: 10.1038/s41467-023-36811-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Accepted: 02/16/2023] [Indexed: 02/26/2023] Open
Abstract
Dual-comb spectroscopy has been proven beneficial in molecular characterization but remains challenging in the mid-infrared region due to difficulties in sources and efficient photodetection. Here we introduce cross-comb spectroscopy, in which a mid-infrared comb is upconverted via sum-frequency generation with a near-infrared comb of a shifted repetition rate and then interfered with a spectral extension of the near-infrared comb. We measure CO2 absorption around 4.25 µm with a 1-µm photodetector, exhibiting a 233-cm-1 instantaneous bandwidth, 28000 comb lines, a single-shot signal-to-noise ratio of 167 and a figure of merit of 2.4 × 106 Hz1/2. We show that cross-comb spectroscopy can have superior signal-to-noise ratio, sensitivity, dynamic range, and detection efficiency compared to other dual-comb-based methods and mitigate the limits of the excitation background and detector saturation. This approach offers an adaptable and powerful spectroscopic method outside the well-developed near-IR region and opens new avenues to high-performance frequency-comb-based sensing with wavelength flexibility.
Collapse
Affiliation(s)
- Mingchen Liu
- Department of Electrical Engineering, California Institute of Technology, Pasadena, CA, 91125, USA
| | - Robert M Gray
- Department of Electrical Engineering, California Institute of Technology, Pasadena, CA, 91125, USA
| | - Luis Costa
- Department of Electrical Engineering, California Institute of Technology, Pasadena, CA, 91125, USA
| | - Charles R Markus
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA, 91125, USA
| | - Arkadev Roy
- Department of Electrical Engineering, California Institute of Technology, Pasadena, CA, 91125, USA
| | - Alireza Marandi
- Department of Electrical Engineering, California Institute of Technology, Pasadena, CA, 91125, USA.
| |
Collapse
|
21
|
Barh A, Nussbaum-Lapping A, Heidrich J, Gaulke M, Golling M, Phillips CR, Keller U. Single-cavity dual-modelocked 2.36-µm laser. OPTICS EXPRESS 2023; 31:6475-6483. [PMID: 36823902 DOI: 10.1364/oe.481789] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/24/2022] [Accepted: 01/21/2023] [Indexed: 06/18/2023]
Abstract
We present the first dual-modelocked femtosecond oscillator operating beyond 2 µm wavelength. This new class of laser is based on a Cr:ZnS gain medium, an InGaSb SESAM for modelocking, and a two-surface reflective device for spatial duplexing of the two modelocked pulse trains (combs). The laser operates at 2.36 µm, and for each comb, we have achieved a FWHM spectral bandwidth of 30 nm, an average power of over 200 mW, and a pulse duration close to 200 fs. The nominal repetition rate is 242 MHz with a sufficiently large repetition rate difference of 4.17 kHz. We also found that the laser is able to produce stable modelocked pulses over a wide range of output powers. This result represents a significant step towards realizing dual-comb applications directly above 2 µm using a single free-running laser.
Collapse
|
22
|
Elkhazraji A, Shakfa MK, Lamperti M, Hakimov K, Djebbi K, Gotti R, Gatti D, Marangoni M, Farooq A. High-resolution molecular fingerprinting in the 11.6-15 µm range by a quasi-CW difference-frequency-generation laser source. OPTICS EXPRESS 2023; 31:4164-4178. [PMID: 36785391 DOI: 10.1364/oe.480107] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/04/2022] [Accepted: 01/02/2023] [Indexed: 06/18/2023]
Abstract
We report an approach for high-resolution spectroscopy using a widely tunable laser emitting in the molecular fingerprint region. The laser is based on difference-frequency generation (DFG) in a nonlinear orientation-patterned GaAs crystal. The signal laser, a CO2 gas laser, is operated in a kHz-pulsed mode while the pump laser, an external-cavity quantum cascade laser, is finely mode-hop-free tuned. The idler radiation covers a spectral range of ∼11.6-15 µm with a laser linewidth of ∼ 2.3 MHz. We showcase the versatility and the potential for molecular fingerprinting of the developed DFG laser source by resolving the absorption features of a mixture of several species in the long-wavelength mid-infrared. Furthermore, exploiting the wide tunability and resolution of the spectrometer, we resolve the broadband absorption spectrum of ethylene (C2H4) over ∼13-14.2 µm and quantify the self-broadening coefficients of some selected spectral lines.
Collapse
|
23
|
Teng CC, Westberg J, Wysocki G. Gapless tuning of quantum cascade laser frequency combs with external cavity optical feedback. OPTICS LETTERS 2023; 48:363-366. [PMID: 36638458 DOI: 10.1364/ol.478950] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/26/2022] [Accepted: 12/09/2022] [Indexed: 06/17/2023]
Abstract
We present the operation of quantum cascade laser frequency combs in an external cavity configuration. Experimental observations show dependence of comb repetition rate and optical spectrum on the external cavity length. The low phase-noise comb regime is extended to a broader range of bias currents, enabling gapless frequency tuning of the comb modes. Dual-comb measurements also confirm improved comb stability in the presence of unwanted optical feedback when operating in an external cavity configuration. These observations indicate that aside from the continuing efforts to assure low and uniform dispersion characteristics of quantum cascade laser frequency combs, the proposed simple approach of adding a broadband external cavity can significantly enhance operation of sub-optimal devices for spectroscopic applications.
Collapse
|
24
|
Guo Q, Zhang J, Yang K, Zhu Y, Lu Q, Zhuo N, Zhai S, Liu J, Wang L, Liu S, Liu F. Monolithically integrated mid-infrared sensor with a millimeter-scale sensing range. OPTICS EXPRESS 2022; 30:40657-40665. [PMID: 36298996 DOI: 10.1364/oe.472667] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/07/2022] [Accepted: 10/04/2022] [Indexed: 06/16/2023]
Abstract
On-chip sensors based on quantum cascade laser technology are attracting broad attention because of their extreme compactness and abundant absorption fingerprints in the mid-infrared wavelength range. Recent continuous wave operation microcavity quantum cascade lasers are well suited for high-density optoelectronic integration because their volumes are small and thresholds are low. In this experimental work, we demonstrate a monolithically integrated sensor comprising a notched elliptical resonator as transmitter, a quantum cascade detector as receiver, and a surface plasmon structure as light-sensing waveguide. The sensor structure is designed to exploit the highly unidirectional lasing properties of the notched elliptical resonator to increase the optical absorption path length. Combined with the evanescent nature of the dielectric loaded surface plasmon polariton waveguides, the structure also ensures a strong light-matter interactions. The sensing transmission distance obtained is approximately 1.16 mm, which is about one order of magnitude improvement over the traditional Fabry-Perot waveguide. This sensor opens new opportunities for long-range and high-sensitivity on-chip gas sensing and spectroscopy.
Collapse
|
25
|
Hillbrand J, Bertrand M, Wittwer V, Opačak N, Kapsalidis F, Gianella M, Emmenegger L, Schwarz B, Südmeyer T, Beck M, Faist J. Synchronization of frequency combs by optical injection. OPTICS EXPRESS 2022; 30:36087-36095. [PMID: 36258545 DOI: 10.1364/oe.456775] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/22/2022] [Accepted: 08/24/2022] [Indexed: 06/16/2023]
Abstract
Optical frequency combs based on semiconductor lasers are a promising technology for monolithic integration of dual-comb spectrometers. However, the stabilization of offset frequency fceo remains a challenging feat due the lack of octave-spanning spectra. In a dual-comb configuration, the uncorrelated jitter of the offset frequencies leads to a non-periodic signal resulting in broadened beatnotes with a limited signal-to-noise ratio (SNR). Hence, expensive data acquisition schemes and complex signal processing are currently required. Here, we show that the offset frequencies of two frequency combs can be synchronized by optical injection locking, which allows full phase-stabilization when combined with electrical injection locking of both repetition frequencies frep. A single comb line isolated via an optical Vernier filter serves as Master oscillator for injection locking. The resulting dual-comb signal is periodic and stable over thousands of periods. This enables coherent averaging using analog electronics, which increases the SNR and reduces the data size by one and three orders of magnitude, respectively. The presented method will enable fully phase-stabilized dual-comb spectrometers by leveraging on integrated optical filters and provides access for comparing and stabilizing fceo to narrow-linewidth optical references.
Collapse
|
26
|
A mid-infrared lab-on-a-chip for dynamic reaction monitoring. Nat Commun 2022; 13:4753. [PMID: 35963870 PMCID: PMC9376098 DOI: 10.1038/s41467-022-32417-7] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2022] [Accepted: 07/29/2022] [Indexed: 11/08/2022] Open
Abstract
Mid-infrared spectroscopy is a sensitive and selective technique for probing molecules in the gas or liquid phase. Investigating chemical reactions in bio-medical applications such as drug production is recently gaining particular interest. However, monitoring dynamic processes in liquids is commonly limited to bulky systems and thus requires time-consuming offline analytics. In this work, we show a next-generation, fully-integrated and robust chip-scale sensor for online measurements of molecule dynamics in a liquid solution. Our fingertip-sized device utilizes quantum cascade technology, combining the emitter, sensing section and detector on a single chip. This enables real-time measurements probing only microliter amounts of analyte in an in situ configuration. We demonstrate time-resolved device operation by analyzing temperature-induced conformational changes of the model protein bovine serum albumin in heavy water. Quantitative measurements reveal excellent performance characteristics in terms of sensor linearity, wide coverage of concentrations, extending from 0.075 mg ml-1 to 92 mg ml-1 and a 55-times higher absorbance than state-of-the-art bulky and offline reference systems.
Collapse
|
27
|
Lins E, Andvaag IR, Read S, Rosendahl SM, Burgess IJ. Dual-Frequency Comb Spectroscopy Studies of Ionic Strength Effects in Time-Resolved ATR-SEIRAS. J Electroanal Chem (Lausanne) 2022. [DOI: 10.1016/j.jelechem.2022.116672] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
|
28
|
Chen D, Sun K, Shen Y, Jones AH, Dadey AA, Guo B, McArthur JA, Bank SR, Campbell JC. Frequency behavior of AlInAsSb nBn photodetectors and the development of an equivalent circuit model. OPTICS EXPRESS 2022; 30:25262-25276. [PMID: 36237060 DOI: 10.1364/oe.457057] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/24/2022] [Accepted: 06/15/2022] [Indexed: 06/16/2023]
Abstract
We report the frequency response of Al0.3InAsSb/Al0.7InAsSb nBn photodetectors. The 3-dB bandwidth of the devices varies from ∼ 150 MHz to ∼ 700 MHz with different device diameters and saturates with bias voltage immediately after the device turn on. A new equivalent circuit model is developed to explain the frequency behavior of nBn photodetectors. The simulated bandwidth based on the new equivalent circuit model agrees well with the bandwidth and the microwave scattering parameter measurements. The analysis reveals that the limiting factor of the bandwidth of the nBn photodetector is the large diffusion capacitance caused by the minority carrier lifetime and the device area. Additionally, the bandwidth of the nBn photodetector is barely affected by the photocurrent, which is found to be caused by the barrier structure in the nBn photodetector.
Collapse
|
29
|
Predicting early failure of quantum cascade lasers during accelerated burn-in testing using machine learning. Sci Rep 2022; 12:9184. [PMID: 35654815 PMCID: PMC9163159 DOI: 10.1038/s41598-022-13303-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2022] [Accepted: 05/16/2022] [Indexed: 11/08/2022] Open
Abstract
Device life time is a significant consideration in the cost of ownership of quantum cascade lasers (QCLs). The life time of QCLs beyond an initial burn-in period has been studied previously; however, little attention has been given to predicting premature device failure where the device fails within several hundred hours of operation. Here, we demonstrate how standard electrical and optical device measurements obtained during an accelerated burn-in process can be used in a simple support vector machine to predict premature failure with high confidence. For every QCL that fails, at least one of the measurements is classified as belonging to a device that will fail prematurely-as much as 200 h before the actual failure of the device. Furthermore, for devices that are operational at the end of the burn-in process, the algorithm correctly classifies all the measurements. This work will influence future device analysis and could lead to insights on the physical mechanisms of premature failure in QCLs.
Collapse
|
30
|
Schubert L, Langner P, Ehrenberg D, Lorenz-Fonfria VA, Heberle J. Protein conformational changes and protonation dynamics probed by a single shot using quantum-cascade-laser-based IR spectroscopy. J Chem Phys 2022; 156:204201. [PMID: 35649857 DOI: 10.1063/5.0088526] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Mid-IR spectroscopy is a powerful and label-free technique to investigate protein reactions. In this study, we use quantum-cascade-laser-based dual-comb spectroscopy to probe protein conformational changes and protonation events by a single-shot experiment. By using a well-characterized membrane protein, bacteriorhodopsin, we provide a comparison between dual-comb spectroscopy and our homebuilt tunable quantum cascade laser (QCL)-based scanning spectrometer as tools to monitor irreversible reactions with high time resolution. In conclusion, QCL-based infrared spectroscopy is demonstrated to be feasible for tracing functionally relevant protein structural changes and proton translocations by single-shot experiments. Thus, we envisage a bright future for applications of this technology for monitoring the kinetics of irreversible reactions as in (bio-)chemical transformations.
Collapse
Affiliation(s)
- Luiz Schubert
- Experimental Molecular Biophysics, Department of Physics, Freie Universität Berlin, Arnimallee 14, 14195 Berlin, Germany
| | - Pit Langner
- Experimental Molecular Biophysics, Department of Physics, Freie Universität Berlin, Arnimallee 14, 14195 Berlin, Germany
| | - David Ehrenberg
- Experimental Molecular Biophysics, Department of Physics, Freie Universität Berlin, Arnimallee 14, 14195 Berlin, Germany
| | - Victor A Lorenz-Fonfria
- Institute of Molecular Science, Universitat de Valencia, Catedrático José Beltrán Martínez, No. 2, 46980 Paterna, Spain
| | - Joachim Heberle
- Experimental Molecular Biophysics, Department of Physics, Freie Universität Berlin, Arnimallee 14, 14195 Berlin, Germany
| |
Collapse
|
31
|
Bauer CP, Camenzind SL, Pupeikis J, Willenberg B, Phillips CR, Keller U. Dual-comb optical parametric oscillator in the mid-infrared based on a single free-running cavity. OPTICS EXPRESS 2022; 30:19904-19921. [PMID: 36221754 DOI: 10.1364/oe.459305] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/25/2022] [Accepted: 05/02/2022] [Indexed: 06/16/2023]
Abstract
We demonstrate a free-running single-cavity dual-comb optical parametric oscillator (OPO) pumped by a single-cavity dual-comb solid-state laser. The OPO ring cavity contains a single periodically-poled MgO-doped LiNbO3 (PPLN) crystal. Each idler beam has more than 245-mW average power at 3550 nm and 3579 nm center wavelengths (bandwidth 130 nm). The signal beams are simultaneously outcoupled with more than 220 mW per beam at 1499 nm and 1496 nm center wavelength. The nominal repetition rate is 80 MHz, while the repetition rate difference is tunable and set to 34 Hz. To evaluate the feasibility of using this type of source for dual-comb applications, we characterize the noise and coherence properties of the OPO signal beams. We find ultra-low relative intensity noise (RIN) below -158 dBc/Hz at offset frequencies above 1 MHz. A heterodyne beat note measurement with a continuous wave (cw) laser is performed to determine the linewidth of a radio-frequency (RF) comb line. We find a full-width half-maximum (FWHM) linewidth of around 400 Hz. Moreover, the interferometric measurement between the two signal beams reveals a surprising property: the center of the corresponding RF spectrum is always near zero frequency, even when tuning the pump repetition rate difference or the OPO cavity length. We explain this effect theoretically and discuss its implications for generating stable low-noise idler combs suitable for high-sensitivity mid-infrared dual-comb spectroscopy (DCS).
Collapse
|
32
|
Wang Q, Wang Z, Zhang H, Jiang S, Wang Y, Jin W, Ren W. Dual-comb photothermal spectroscopy. Nat Commun 2022; 13:2181. [PMID: 35449158 PMCID: PMC9023540 DOI: 10.1038/s41467-022-29865-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2021] [Accepted: 04/05/2022] [Indexed: 11/26/2022] Open
Abstract
Dual-comb spectroscopy (DCS) has revolutionized optical spectroscopy by providing broadband spectral measurements with unprecedented resolution and fast response. Photothermal spectroscopy (PTS) with a pump-probe configuration offers a highly sensitive gas sensing method, which is normally performed using a single-wavelength pump laser. The merging of PTS with DCS may enable a spectroscopic method by taking advantage of both technologies, which has never been studied yet. Here, we report dual-comb photothermal spectroscopy (DC-PTS) by passing dual combs and a probe laser through a gas-filled anti-resonant hollow-core fiber, where the generated multi-heterodyne modulation of the refractive index is sensitively detected by an in-line interferometer. As an example, we have measured photothermal spectra of acetylene over 1 THz, showing a good agreement with the spectral database. Our proposed DC-PTS provides opportunities for broadband gas sensing with super-fine resolution and high sensitivity, as well as with a small sample volume and compact configuration. 'Recent developments in spectroscopy have witnessed the establishment of dual-comb techniques. In this work the authors demonstrate dual-comb photothermal spectroscopy providing gas sensing with superfine resolution and high sensitivity
Collapse
Affiliation(s)
- Qiang Wang
- State Key Laboratory of Applied Optics, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, 130033, Changchun, China. .,University of Chinese Academy of Sciences, 100049, Beijing, China.
| | - Zhen Wang
- Department of Mechanical and Automation Engineering, and Shenzhen Research Institute, The Chinese University of Hong Kong, New Territories, Hong Kong SAR, China.
| | - Hui Zhang
- State Key Laboratory of Applied Optics, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, 130033, Changchun, China.,University of Chinese Academy of Sciences, 100049, Beijing, China
| | - Shoulin Jiang
- Department of Electrical Engineering, The Hong Kong Polytechnic University, Kowloon, Hong Kong SAR, China
| | - Yingying Wang
- Institute of Photonics Technology, Jinan University, 510632, Guangzhou, China
| | - Wei Jin
- Department of Electrical Engineering, The Hong Kong Polytechnic University, Kowloon, Hong Kong SAR, China
| | - Wei Ren
- Department of Mechanical and Automation Engineering, and Shenzhen Research Institute, The Chinese University of Hong Kong, New Territories, Hong Kong SAR, China.
| |
Collapse
|
33
|
Komagata KN, Gianella M, Jouy P, Kapsalidis F, Shahmohammadi M, Beck M, Matthey R, Wittwer VJ, Hugi A, Faist J, Emmenegger L, Südmeyer T, Schilt S. Absolute frequency referencing in the long wave infrared using a quantum cascade laser frequency comb. OPTICS EXPRESS 2022; 30:12891-12901. [PMID: 35472915 DOI: 10.1364/oe.447650] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/23/2021] [Accepted: 02/01/2022] [Indexed: 06/14/2023]
Abstract
Optical frequency combs (OFCs) based on quantum cascade lasers (QCLs) have transformed mid-infrared spectroscopy. However, QCL-OFCs have not yet been exploited to provide a broadband absolute frequency reference. We demonstrate this possibility by performing comb-calibrated spectroscopy at 7.7 µm (1305 cm-1) using a QCL-OFC referenced to a molecular transition. We obtain 1.5·10-10 relative frequency stability (100-s integration time) and 3·10-9 relative frequency accuracy, comparable with state-of-the-art solutions relying on nonlinear frequency conversion. We show that QCL-OFCs can be locked with sub-Hz-level stability to a reference for hours, thus promising their use as metrological tools for the mid-infrared.
Collapse
|
34
|
Corrias N, Gabbrielli T, De Natale P, Consolino L, Cappelli F. Analog FM free-space optical communication based on a mid-infrared quantum cascade laser frequency comb. OPTICS EXPRESS 2022; 30:10217-10228. [PMID: 35472994 DOI: 10.1364/oe.443483] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/23/2021] [Accepted: 11/08/2021] [Indexed: 06/14/2023]
Abstract
Quantum cascade laser frequency combs are nowadays well-appreciated sources for infrared spectroscopy. Here their applicability for free-space optical communication is demonstrated. The spontaneously-generated intermodal beat note of the frequency comb is used as carrier for transferring the analog signal via frequency modulation. Exploiting the atmospheric transparency window at 4 µm, an optical communication with a signal-to-noise ratio up to 65 dB is realized, with a modulation bandwidth of 300 kHz. The system tolerates a maximum optical attenuation exceeding 35 dB. The possibility of parallel transmission of an independent digital signal via amplitude modulation at 5 Mbit/s is also demonstrated.
Collapse
|
35
|
Abstract
Optical frequency comb technologies have received intense attention due to their numerous promising applications ranging from optical communications to optical comb spectroscopy. In this study, we experimentally demonstrate a new approach of broadband comb generation based on the polarization mode competition in single-mode VCSELs. More specifically, we analyze nonlinear dynamics and polarization properties in VCSELs when subject of optical injection from a frequency comb. When varying injection parameters (injection strength and detuning frequency) and comb properties (comb spacing), we unveil several bifurcation sequences enabling the excitation of free-running depressed polarization mode. Interestingly, for some injection parameters, the polarization mode competition induces a single or a two polarization comb with controllable properties (repetition rate and power per line). We also show that the performance of the two polarization combs depends crucially on the injection current and on the injected comb spacing. We explain our experimental findings by utilizing the spin-flip VCSEL model (SFM) supplemented with terms for parallel optical injection of frequency comb. We provide a comparison between parallel and orthogonal optical injection in the VCSEL when varying injection parameters and SFM parameters. We show that orthogonal comb dynamics can be observed in a wide range of parameters, as for example dichroism linear dichroism (γa=−0.1 ns−1 to γa=−0.8 ns−1), injection current (μ=2.29 to μ=5.29) and spin-flip relaxation rate (γs=50 ns−1 to γs=2300 ns−1).
Collapse
|
36
|
Barh A, Alaydin BÖ, Heidrich J, Gaulke M, Golling M, Phillips CR, Keller U. High-power low-noise 2-GHz femtosecond laser oscillator at 2.4 µm. OPTICS EXPRESS 2022; 30:5019-5025. [PMID: 35209473 DOI: 10.1364/oe.446986] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2021] [Accepted: 01/21/2022] [Indexed: 06/14/2023]
Abstract
Femtosecond lasers with high repetition rates are attractive for spectroscopic applications with high sampling rates, high power per comb line, and resolvable lines. However, at long wavelengths beyond 2 µm, current laser sources are either limited to low output power or repetition rates below 1 GHz. Here we present an ultrafast laser oscillator operating with high output power at multi-GHz repetition rate. The laser produces transform-limited 155-fs pulses at a repetition rate of 2 GHz, and an average power of 0.8 W, reaching up to 0.7 mW per comb line at the center wavelength of 2.38 µm. We have achieved this milestone via a Cr2+-doped ZnS solid-state laser modelocked with an InGaSb/GaSb SESAM. The laser is stable over several hours of operation. The integrated relative intensity noise is 0.15% rms for [10 Hz, 100 MHz], and the laser becomes shot noise limited (-160 dBc/Hz) at frequencies above 10 MHz. Our timing jitter measurements reveal contributions from pump laser noise and relaxation oscillations, with a timing jitter of 100 fs integrated over [3 kHz, 100 MHz]. These results open up a path towards fast and sensitive spectroscopy directly above 2 µm.
Collapse
|
37
|
Humbard L, Burghoff D. Analytical theory of frequency-modulated combs: generalized mean-field theory, complex cavities, and harmonic states. OPTICS EXPRESS 2022; 30:5376-5401. [PMID: 35209502 DOI: 10.1364/oe.445570] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/12/2021] [Accepted: 12/22/2021] [Indexed: 06/14/2023]
Abstract
Frequency-modulated (FM) combs with a linearly-chirped frequency and nearly constant intensity occur naturally in certain laser systems; they can be most succinctly described by a nonlinear Schrödinger equation with a phase potential. In this work, we perform a comprehensive analytical study of FM combs in order to calculate their salient properties. We develop a general procedure that allows mean-field theories to be constructed for arbitrary sets of master equations, and as an example consider the case of reflective defects. We derive an expression for the FM chirp of arbitrary Fabry-Perot cavities-important for most realistic lasers-and use perturbation theory to show how they are affected by finite gain bandwidth and linewidth enhancment in fast gain media. Lastly, we show that an eigenvalue formulation of the laser's dynamics can be useful for characterizing all of the stable states of the laser: the fundamental comb, the continuous-wave solution, and the harmonic states.
Collapse
|
38
|
Gianella M, Vogel S, Wittwer VJ, Südmeyer T, Faist J, Emmenegger L. Frequency axis for swept dual-comb spectroscopy with quantum cascade lasers. OPTICS LETTERS 2022; 47:625-628. [PMID: 35103695 DOI: 10.1364/ol.446347] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/05/2021] [Accepted: 12/20/2021] [Indexed: 06/14/2023]
Abstract
In dual-comb spectroscopy, there is a one-to-one map between the frequencies of the measured beat notes and the frequencies of the optical comb lines. Its determination usually involves the use of one or more reference lasers with known frequencies. Quantum cascade laser frequency combs, however, are often operated in a free-running mode, and without a reference, the determination of the RF-to-optical frequency map is not trivial. Here, we propose a method by which the comb shift is measured with an unbalanced Mach-Zehnder interferometer, and the spectral point spacing is determined through the intermode beat measured on the laser electrodes. The frequency axis is accurate within ∼ 0.001 cm-1.
Collapse
|
39
|
Liang CT, Wu YY, Wang ZB, Li PC. Evolution of the frequency-comb structure and coherence from a Keldysh multiphoton into a tunneling regime. OPTICS EXPRESS 2022; 30:2413-2423. [PMID: 35209382 DOI: 10.1364/oe.449442] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/23/2021] [Accepted: 12/21/2021] [Indexed: 06/14/2023]
Abstract
We present a theoretical study of the characteristics of the frequency-comb structure and coherence via high-order harmonic generation (HHG) driven by the laser pulse trains when the ionization process is pushed from Keldysh multiphoton into tunneling regime. HHG is obtained by solving accurately the time-dependent Schrödinger equation by means of the time-dependent generalized pseudospectral method. We find that the nested comb structures are formed from each harmonic order in the Keldysh multiphoton ionization regime. But it is severely suppressed or even disappeared in the Keldysh tunneling ionization regime. It implies that the temporal coherence of the emitted frequency comb modes is very sensitive to the Keldysh ionization regime. To understand the evolution of frequency-comb structure and coherence, we perform the calculation of the time-dependent ionization probability and the spectral phase of frequency-comb HHG. We find that the frequency-comb HHG driven by the laser pulse trains in the Keldysh multiphoton regime has a good coherence because the ionization probability of the atom driven by each laser pulse is stable, leading to a phase-coherent frequency-comb structure rather than those cases in the Keldysh tunneling regime with high laser intensity. Our results shed light on current interest and significance to the experimental realization of controllable and frequency-comb vacuum-ultraviolet light sources.
Collapse
|
40
|
Stroud JR, Simon JB, Wagner GA, Plusquellic DF. Interleaved electro-optic dual comb generation to expand bandwidth and scan rate for molecular spectroscopy and dynamics studies near 1.6 µm. OPTICS EXPRESS 2021; 29:33155-33170. [PMID: 34809133 DOI: 10.1364/oe.434482] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/18/2021] [Accepted: 09/18/2021] [Indexed: 06/13/2023]
Abstract
A chirped-pulse interleaving method is reported for generation of dual optical frequency combs based on electro-optic phase modulators (EOM) in a free-running all-fiber based system. Methods are discussed to easily modify the linear scan rate and comb resolution by more than three orders of magnitude and to significantly increase the spectral bandwidth coverage. The agility of the technique is shown to both capture complex line shapes and to magnify rapid passage effects in spectroscopic and molecular dynamics studies of CO2. These methods are well-suited for applications in the areas of remote sensing of greenhouse gas emissions, molecular reaction dynamics, and sub-Doppler studies across the wide spectral regions accessible to EOMs.
Collapse
|
41
|
Wang C, Li Z, Liao X, Guan W, Ma X, Zhou K, Cao JC, Li H. Improved comb and dual-comb operation of terahertz quantum cascade lasers utilizing a symmetric thermal dissipation. OPTICS EXPRESS 2021; 29:29412-29422. [PMID: 34615051 DOI: 10.1364/oe.433938] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/11/2021] [Accepted: 08/13/2021] [Indexed: 06/13/2023]
Abstract
In the terahertz frequency range, the quantum cascade laser (QCL) is a suitable platform for the frequency comb and dual-comb operation. Improved comb performances have been always much in demand. In this work, by employing a symmetric thermal dissipation scheme, we report an improved frequency comb and dual-comb operation of terahertz QCLs. Two configurations of cold fingers, i.e., type A and B with asymmetric and symmetric thermal dissipation schemes, respectively, are investigated here. A finite-element thermal analysis is carried out to study the parametric effects on the thermal management of the terahertz QCL. The modeling reveals that the symmetric thermal dissipation (type B) results in a more uniform thermal conduction and lower maximum temperature in the active region of the laser, compared to the traditional asymmetric thermal dissipation scheme (type A). To verify the simulation, experiments are further performed by measuring laser performance and comb characteristics of terahertz QCLs emitting around 4.2 THz mounted on type A and type B cold fingers. The experimental results show that the symmetric thermal dissipation approach (type B) is effective for improving the comb and dual-comb operation of terahertz QCLs, which can be further widely adopted for spectroscopy, imaging, and near-field applications.
Collapse
|
42
|
Beiser M, Opačak N, Hillbrand J, Strasser G, Schwarz B. Engineering the spectral bandwidth of quantum cascade laser frequency combs. OPTICS LETTERS 2021; 46:3416-3419. [PMID: 34264227 DOI: 10.1364/ol.424164] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Accepted: 05/11/2021] [Indexed: 06/13/2023]
Abstract
Quantum cascade lasers (QCLs) facilitate compact optical frequency comb sources that operate in the mid-infrared and terahertz spectral regions, where many molecules have their fundamental absorption lines. Enhancing the optical bandwidth of these chip-sized lasers is of paramount importance to address their application in broadband high-precision spectroscopy. In this work, we provide a numerical and experimental investigation of the comb spectral width and show how it can be optimized to obtain its maximum value defined by the laser gain bandwidth. The interplay of nonoptimal values of the resonant Kerr nonlinearity and cavity dispersion can lead to significant narrowing of the comb spectrum and reveals the best approach for dispersion compensation. The implementation of high mirror losses is shown to be favorable and results in proliferation of the comb sidemodes. Ultimately, injection locking of QCLs by modulating the laser bias around the round trip frequency provides a stable external knob to control the frequency-modulated comb state and recover the maximum spectral width of the unlocked laser state.
Collapse
|
43
|
Abstract
Multiheterodyne techniques using frequency combs-radiation sources whose lines are perfectly evenly-spaced-have revolutionized science. By beating sources with the many lines of a comb, their spectra are recovered. Even so, these approaches are fundamentally limited to probing coherent sources, such as lasers. They are unable to measure most spectra that occur in nature. Here we present frequency comb ptychoscopy, a technique that allows for the spectrum of any complex broadband source to be retrieved using a comb. In this approach, the spectrum is reconstructed by unfolding the simultaneous beating of a source with each comb line. We demonstrate this both theoretically and experimentally, at microwave frequencies. This approach can reconstruct the spectrum of nearly any complex source to high resolution, and the speed, resolution, and generality of this technique will allow chip-scale frequency combs to have an impact in a wide swath of new applications, such as remote sensing and passive spectral imaging.
Collapse
|
44
|
Fukuda T, Okano M, Watanabe S. Interferogram-based determination of the absolute mode numbers of optical frequency combs in dual-comb spectroscopy. OPTICS EXPRESS 2021; 29:22214-22227. [PMID: 34265991 DOI: 10.1364/oe.431104] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/11/2021] [Accepted: 06/18/2021] [Indexed: 06/13/2023]
Abstract
Dual-comb spectroscopy (DCS), which uses two optical frequency combs (OFCs), requires an accurate knowledge of the mode number of each comb line to determine spectral features. We demonstrate a fast evaluation method of the absolute mode numbers of both OFCs used in DCS system. By measuring the interval between the peaks in the time-domain interferogram, it is possible to accurately determine the ratio of one OFC repetition frequency (frep) to the difference between the frep values of the two OFCs (Δfrep). The absolute mode numbers can then be straightforwardly calculated using this ratio. This method is applicable to a broad range of Δfrep values down to several Hz without any additional instruments. For instance, the minimum required measurement time is estimated to be about 1 s for Δfrep ≈ 5.6 Hz and frep ≈ 60 MHz. The optical frequencies of the absorption lines of acetylene gas obtained by DCS with our method of mode number determination shows good agreement with the data from the HITRAN database.
Collapse
|
45
|
Valušis G, Lisauskas A, Yuan H, Knap W, Roskos HG. Roadmap of Terahertz Imaging 2021. SENSORS (BASEL, SWITZERLAND) 2021; 21:4092. [PMID: 34198603 PMCID: PMC8232131 DOI: 10.3390/s21124092] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Revised: 06/07/2021] [Accepted: 06/08/2021] [Indexed: 01/01/2023]
Abstract
In this roadmap article, we have focused on the most recent advances in terahertz (THz) imaging with particular attention paid to the optimization and miniaturization of the THz imaging systems. Such systems entail enhanced functionality, reduced power consumption, and increased convenience, thus being geared toward the implementation of THz imaging systems in real operational conditions. The article will touch upon the advanced solid-state-based THz imaging systems, including room temperature THz sensors and arrays, as well as their on-chip integration with diffractive THz optical components. We will cover the current-state of compact room temperature THz emission sources, both optolectronic and electrically driven; particular emphasis is attributed to the beam-forming role in THz imaging, THz holography and spatial filtering, THz nano-imaging, and computational imaging. A number of advanced THz techniques, such as light-field THz imaging, homodyne spectroscopy, and phase sensitive spectrometry, THz modulated continuous wave imaging, room temperature THz frequency combs, and passive THz imaging, as well as the use of artificial intelligence in THz data processing and optics development, will be reviewed. This roadmap presents a structured snapshot of current advances in THz imaging as of 2021 and provides an opinion on contemporary scientific and technological challenges in this field, as well as extrapolations of possible further evolution in THz imaging.
Collapse
Affiliation(s)
- Gintaras Valušis
- Center for Physical Sciences and Technology (FTMC), Department of Optoelectronics, Saulėtekio Ave. 3, LT-10257 Vilnius, Lithuania
- Institute of Photonics and Nanotechnology, Department of Physics, Vilnius University, Saulėtekio Ave. 3, LT-10257 Vilnius, Lithuania
| | - Alvydas Lisauskas
- Institute of Applied Electrodynamics and Telecommunications, Vilnius University, Saulėtekio Ave. 3, LT-10257 Vilnius, Lithuania;
- CENTERA Laboratories, Institute of High Pressure Physics PAS, Sokolowska 29/37, 01-142 Warsaw, Poland;
| | - Hui Yuan
- Physikalisches Institut, Goethe-Universität, Max-von-Laue Straße 1, D-60438 Frankfurt am Main, Germany; (H.Y.); (H.G.R.)
| | - Wojciech Knap
- CENTERA Laboratories, Institute of High Pressure Physics PAS, Sokolowska 29/37, 01-142 Warsaw, Poland;
| | - Hartmut G. Roskos
- Physikalisches Institut, Goethe-Universität, Max-von-Laue Straße 1, D-60438 Frankfurt am Main, Germany; (H.Y.); (H.G.R.)
| |
Collapse
|
46
|
Komagata K, Shehzad A, Terrasanta G, Brochard P, Matthey R, Gianella M, Jouy P, Kapsalidis F, Shahmohammadi M, Beck M, Wittwer VJ, Faist J, Emmenegger L, Südmeyer T, Hugi A, Schilt S. Coherently-averaged dual comb spectrometer at 7.7 µm with master and follower quantum cascade lasers. OPTICS EXPRESS 2021; 29:19126-19139. [PMID: 34154154 DOI: 10.1364/oe.425480] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Accepted: 05/18/2021] [Indexed: 06/13/2023]
Abstract
We demonstrate coherent averaging of the multi-heterodyne beat signal between two quantum cascade laser frequency combs in a master-follower configuration. The two combs are mutually locked by acting on the drive current to control their relative offset frequency and by radio-frequency extraction and injection locking of their intermode beat signal to stabilize their mode spacing difference. By implementing an analog common-noise subtraction scheme, a reduction of the linewidth of all heterodyne beat notes by five orders of magnitude is achieved compared to the free-running lasers. We compare stabilization and post-processing corrections in terms of amplitude noise. While they give similar performances in terms of signal-to-noise ratio, real-time processing of the stabilized signal is less demanding in terms of computational power. Lastly, a proof-of-principle spectroscopic measurement was performed, showing the possibility to reduce the amount of data to be processed by three orders of magnitude, compared to the free-running system.
Collapse
|
47
|
Columbo L, Piccardo M, Prati F, Lugiato LA, Brambilla M, Gatti A, Silvestri C, Gioannini M, Opačak N, Schwarz B, Capasso F. Unifying Frequency Combs in Active and Passive Cavities: Temporal Solitons in Externally Driven Ring Lasers. PHYSICAL REVIEW LETTERS 2021; 126:173903. [PMID: 33988397 DOI: 10.1103/physrevlett.126.173903] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/08/2020] [Accepted: 03/29/2021] [Indexed: 06/12/2023]
Abstract
Frequency combs have become a prominent research area in optics. Of particular interest as integrated comb technology are chip-scale sources, such as semiconductor lasers and microresonators, which consist of resonators embedding a nonlinear medium either with or without population inversion. Such active and passive cavities were so far treated distinctly. Here we propose a formal unification by introducing a general equation that describes both types of cavities. The equation also captures the physics of a hybrid device-a semiconductor ring laser with an external optical drive-in which we show the existence of temporal solitons, previously identified only in microresonators, thanks to symmetry breaking and self-localization phenomena typical of spatially extended dissipative systems.
Collapse
Affiliation(s)
- L Columbo
- Dipartimento di Elettronica e Telecomunicazioni, Politecnico di Torino, 10129 Torino, Italy
- CNR-Istituto di Fotonica e Nanotecnologie, 70126 Bari, Italy
| | - M Piccardo
- Center for Nano Science and Technology, Fondazione Istituto Italiano di Tecnologia, 20133 Milano, Italy
- Harvard John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02134, USA
| | - F Prati
- Dipartimento di Scienza e Alta Tecnologia, Università dell'Insubria, 22100 Como, Italy
| | - L A Lugiato
- Dipartimento di Scienza e Alta Tecnologia, Università dell'Insubria, 22100 Como, Italy
| | - M Brambilla
- Dipartimento di Fisica Interateneo and CNR-IFN, Università e Politecnico di Bari, 70125 Bari, Italy
| | - A Gatti
- Dipartimento di Scienza e Alta Tecnologia, Università dell'Insubria, 22100 Como, Italy
- Istituto di Fotonica e Nanotecnologie IFN-CNR, 20133 Milano, Italy
| | - C Silvestri
- Dipartimento di Elettronica e Telecomunicazioni, Politecnico di Torino, 10129 Torino, Italy
| | - M Gioannini
- Dipartimento di Elettronica e Telecomunicazioni, Politecnico di Torino, 10129 Torino, Italy
| | - N Opačak
- Institute of Solid State Electronics, TU Wien, 1040 Vienna, Austria
| | - B Schwarz
- Institute of Solid State Electronics, TU Wien, 1040 Vienna, Austria
| | - F Capasso
- Harvard John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02134, USA
| |
Collapse
|
48
|
Yoon Y, Breshike CJ, Kendziora CA, Furstenberg R, Andrew McGill R. Simultaneous real-time spectroscopy using a broadband IR laser source. OPTICS EXPRESS 2021; 29:8902-8913. [PMID: 33820331 DOI: 10.1364/oe.419262] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Accepted: 02/20/2021] [Indexed: 06/12/2023]
Abstract
In this study, we have developed a simultaneous grating spectroscopy using a broadband IR laser source capable of detecting moving targets in real time. The broadband IR laser source operated in pulsed mode provides a broad spectral range, which covers absorption bands of many chemical analytes. The laser operating conditions were optimized to cover the broadest wavelength range spanning spectral features for the analytes of interest, based on a detailed understanding of the broadband source. This measured the signal from two samples, a 1% acetaminophen KBr pellet sample and toluene in a gas cell. These samples were characterized by illuminating them with the IR broadband source and collecting the transmitted or reflected signal through a grating spectrometer and onto an IR focal plane array (FPA). The results clearly show discrete peaks comparable to the FTIR reference spectra and the spectral features of the samples were successfully discriminated. We believe that the proof of concepts presented here are of broad applicability and will aid advanced real-time standoff detection research.
Collapse
|
49
|
Hillbrand J, Matthieu Krüger L, Dal Cin S, Knötig H, Heidrich J, Maxwell Andrews A, Strasser G, Keller U, Schwarz B. High-speed quantum cascade detector characterized with a mid-infrared femtosecond oscillator. OPTICS EXPRESS 2021; 29:5774-5781. [PMID: 33726109 DOI: 10.1364/oe.417976] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Accepted: 01/20/2021] [Indexed: 06/12/2023]
Abstract
Quantum cascade detectors (QCD) are photovoltaic mid-infrared detectors based on intersubband transitions. Owing to the sub-picosecond carrier transport between subbands and the absence of a bias voltage, QCDs are ideally suited for high-speed and room temperature operation. Here, we demonstrate the design, fabrication, and characterization of 4.3 µm wavelength QCDs optimized for large electrical bandwidth. The detector signal is extracted via a tapered coplanar waveguide (CPW), which was impedance-matched to 50 Ω. Using femtosecond pulses generated by a mid-infrared optical parametric oscillator (OPO), we show that the impulse response of the fully packaged QCDs has a full-width at half-maximum of only 13.4 ps corresponding to a 3-dB bandwidth of more than 20 GHz. Considerable detection capability beyond the 3-dB bandwidth is reported up to at least 50 GHz, which allows us to measure more than 600 harmonics of the OPO repetition frequency reaching 38 dB signal-to-noise ratio without the need of electronic amplification.
Collapse
|
50
|
Mizuno T, Nakajima Y, Hata Y, Tsuda T, Asahara A, Kato T, Minamikawa T, Yasui T, Minoshima K. Computationally image-corrected dual-comb microscopy with a free-running single-cavity dual-comb fiber laser. OPTICS EXPRESS 2021; 29:5018-5032. [PMID: 33726045 DOI: 10.1364/oe.415242] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/17/2020] [Accepted: 01/26/2021] [Indexed: 06/12/2023]
Abstract
Dual-comb microscopy (DCM), an interesting imaging modality based on the optical-frequency-comb (OFC) mode and image pixel one-to-one correspondence, benefits from scan-less full-field imaging and simultaneous confocal amplitude and phase imaging. However, the two fully frequency-stabilized OFC sources requirement hampers DCM practicality due to the complexity and costs. Here, a bidirectional single-cavity dual-comb fiber laser (SCDCFL) is adopted as a DCM low-complexity OFC source. Although the residual timing jitter in the SCDCFL blurs the image of a static object acquired by DCM, computational image correction significantly suppresses the image blur. Nanometer-order step surface profilometry with a 14.0 nm uncertainty highlights the computationally image-corrected DCM effectiveness. We further discuss a possibility to expand the computational image correction to a dynamic object and demonstrate its preliminary experiment. The proposed method enhances the DCM generality and practicality due to low-complexity OFC source.
Collapse
|