DOCSLIB.ORG

Time-Domain Investigations of Coherent Phonons in Van Der Waals Thin Films

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Time-Domain Investigations of Coherent Phonons in Van Der Waals Thin Films nanomaterials Review Time-Domain Investigations of Coherent Phonons in van der Waals Thin Films Fabien Vialla * and Natalia Del Fatti Institut Lumière Matière UMR 5306, Université Claude Bernard Lyon 1, CNRS, Université de Lyon, F-69622 Villeurbanne, France; [email protected] * Correspondence: [email protected] Received: 17 November 2020; Accepted: 14 December 2020; Published: 17 December 2020 Abstract: Coherent phonons can be launched in materials upon localized pulsed optical excitation, and be subsequently followed in time-domain, with a sub-picosecond resolution, using a time-delayed pulsed probe. This technique yields characterization of mechanical, optical, and electronic properties at the nanoscale, and is taken advantage of for investigations in material science, physics, chemistry, and biology. Here we review the use of this experimental method applied to the emerging field of homo- and heterostructures of van der Waals materials. Their unique structure corresponding to non-covalently stacked atomically thin layers allows for the study of original structural configurations, down to one-atom-thin films free of interface defect. The generation and relaxation of coherent optical phonons, as well as propagative and resonant breathing acoustic phonons, are comprehensively discussed. This approach opens new avenues for the in situ characterization of these novel materials, the observation and modulation of exotic phenomena, and advances in the field of acoustics microscopy. Keywords: acoustics; coherent phonon; breathing mode; picosecond ultrasonics; time-domain spectroscopy; pump-probe; van der Waals; two-dimensional materials; layered materials; mechanical resonator 1. Introduction Van der Waals (vdW) materials, also referred to as layered two-dimensional (2D) materials, are strongly anisotropic materials formed by layers of covalently bound atoms, stacked on top of each other and linked through vdW forces. Many lattice structures are encountered for the 2D layers, as depicted in Figure1, such as hexagonal one-atom-thick layers in graphite (where monolayers are referred to as graphene) and boron nitride (hBN), two-atom-thick layers in black phosphorous (BP), three-atom-thick layers with octahedral (PbI2, PtSe2 ::: ) or trigonal prismatic coordination (MoS2, WSe2 ::: ) usually referred to as transition metal dichalcogenides (TMDs), four-atom-thick layers (GaS, InSe ::: ), five-atom-thick layers (Sb2Se3, Bi2Te3 ::: ) usually referred to as V2VI3 chalcogenides or as quintuple layers (QLs), and many more complex structures [1,2]. In addition, they present various phases, also referred to as polytypes, related to the stacking alignment order of the layers, which further influence their physical properties [2,3]. In sum, the vdW material family spans the full variety of material classes, from dielectrics to metals, semiconductors with bandgaps from ultraviolet to mid-infrared, ferromagnets, piezoelectrics, superconductors, topological insulators, etc. [4–8]. Importantly, their strong structural anisotropy affects their mechanical, electronic, optical, and thermal properties. These original bulk properties have been under intense characterization during the 1970s and 1980s [1,2,9]. Nanomaterials 2020, 10, 2543; doi:10.3390/nano10122543 www.mdpi.com/journal/nanomaterials Nanomaterials 2020, 10, 2543 2 of 45 Nanomaterials 2020, 10, x FOR PEER REVIEW 2 of 47 (a) (b) (c) (d) (e) (f) Figure 1. FigureSchematics 1. Schematics of a relevant of a relevant subset subset of ofvan van der der Waals Waals materials,materials, which which will will be discussed be discussed in the in the following review. (a) Graphene layers in a Bernal stacking. (b) Black phosphorous. (c) PtSe2 in a 1T following review. (a) Graphene layers in a Bernal stacking. (b) Black phosphorous. (c) PtSe2 in a 1T phase stacking. (d) MoS2 in a 2H phase stacking. (e) InSe in a γ phase stacking. (f) Bi2Te3. phase stacking. (d) MoS2 in a 2H phase stacking. (e) InSe in a γ phase stacking. (f) Bi2Te3. A fresh appeal sprouted out in 2004 with the exploration of vdW materials reduced to a A freshsingle appeal monolayer sprouted after the out first in mechanical2004 with exfoliation the exploration and characterization of vdW materials of graphene reduced from bulk to a single monolayergraphite after the [10, 11first]. Its mechanical unconventional exfoliation structure, and a honeycomb characterization lattice of carbonof graphene atoms forming from bulk a true graphite 2D layer with no dandling bonds out of the plane, is at the origin of many unique features. The most [10,11]. Itsstriking unconventional one may be the structure, gapless, massless a honeycomb Dirac electrons lattice [10 ]of from carbon which atoms arise a spectrallyforming flat a true optical 2D layer with no dandlingabsorption bonds [12] and out many of the exotic plane, quantum is at transport the origin regimes of many [13]. Grapheneunique features. also presents The superior most striking one may thermalbe the [ 14gapless,] and mechanical massless properties Dirac [15electrons]. Likewise, [10] the wholefrom vdWwhich materials arise family a spectrally can be thinned flat optical absorptiondown [12] to and a single many layer, exotic yet sometimes quantum at transport the expense regimes of reduced [13]. chemical Graphene stability. also When presents reduced superior thermal [14]to the and atomic mechanical scale on the out-of-planeproperties dimension,[15]. Likewise, most of thesethe whole materials vdW present materials emerging family original can be properties stemming from quantum confinement and weakly screened charge carriers, for instance thinned downroom-temperature to a single excitonic layer, behaviorsyet sometimes in semiconducting at the expense TMDs [16 of,17 ].reduced Additionally, chemical since single-layer stability. When reduced tomaterials the atomic are only scale composed on the of out-of-plane surface atoms, theydimension, present a deep most tunability of these of materials their properties present through emerging original propertiestheir environment, stemming for instance from viaquantum capacitive conf couplinginement [10,18 and] and weakly Coulomb screened screening [charge19]. However, carriers, for instance room-temperaturethe coupling to an uncontrolled excitonic environment,behaviors in e.g., semiconducting to a substrate or TMDs adsorbed [16,17]. molecules, Additionally, usually since single-layerpredominates materials over are the only intrinsic composed properties. of Thus, surface extrinsically atoms, induced they pr defects,esent inhomogeneities,a deep tunability and a of their dominant energy loss to the substrate were very detrimental in early studies [20–22]. properties throughIt is to circumventtheir environment, these issues for that instance the concept via ofcapacitive vdW heterostructures coupling [10,18] was introduced. and Coulomb screeningGraphene [19]. However, monolayer wasthe firstcoupling transferred to onan top un ofcontrolled hBN [23], and environment, then encapsulated e.g., in-between to a substrate [24], or adsorbedto molecules, achieve passivation usually andpredominates flattening of over the layer. the intrinsic This principle properties. of stacking Thus, diff extrinsicallyerent layers on induced defects, inhomogeneities,top of each other has and been a dominant extended overenergy the loss years to to the the substrate whole family were of vdWvery materialsdetrimental [6,8]. in early studies [20–22].Major nanofabrication challenges have been overcome, in particular concerning the cleanliness of It is to circumvent these issues that the concept of vdW heterostructures was introduced. Graphene monolayer was first transferred on top of hBN [23], and then encapsulated in-between [24], to achieve passivation and flattening of the layer. This principle of stacking different layers on top of each other has been extended over the years to the whole family of vdW materials [6,8]. Major nanofabrication challenges have been overcome, in particular concerning the cleanliness of the interfaces to achieve large scale, homogenous, optimized coupling [25–27]. Selective electrical contacting [28] and control over the relative angle between the layer lattices [29] can be implemented. In parallel, huge improvements have been obtained in the field of material synthesis leading to the successful growth of large-scale, single-crystal layers [30,31]. Chemical exfoliation and sorting processes yield large-scale, high-quality, controllable ensembles of few-layer sheets [32,33]. Nanomaterials 2020, 10, 2543 3 of 45 the interfaces to achieve large scale, homogenous, optimized coupling [25–27]. Selective electrical contacting [28] and control over the relative angle between the layer lattices [29] can be implemented. In parallel, huge improvements have been obtained in the field of material synthesis leading to the successful growth of large-scale, single-crystal layers [30,31]. Chemical exfoliation and sorting processes yield large-scale, high-quality, controllable ensembles of few-layer sheets [32,33]. Moreover, vdW heterostructures can be directly grown via chemical vapor deposition or molecular beam epitaxy [8,34], rather than tedious exfoliation and subsequent stacking of the layers. VdW heterostructure versatility can be further expanded by intercalating atoms or molecules between the layers, or functionalizing the layer surfaces [35,36]. In particular, changing growth stoichiometry of QL materials yields natural superlattices with for instance intercalation
Load more

Recommended publications
  • Nonlinear Ultrafast Acoustics at the Nano Scale Peter Van Capel, Emmanuel Péronne, Jaap Dijkhuis
    Nonlinear ultrafast acoustics at the nano scale Peter van Capel, Emmanuel Péronne, Jaap Dijkhuis To cite this version: Peter van Capel, Emmanuel Péronne, Jaap Dijkhuis. Nonlinear ultrafast acoustics at the nano scale. Ultrasonics, Elsevier, 2015, 56, pp.36-51. 10.1016/j.ultras.2014.09.021. hal-01233796 HAL Id: hal-01233796 https://hal.archives-ouvertes.fr/hal-01233796 Submitted on 17 Oct 2018 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. Nonlinear ultrafast acoustics at the nano scale ⇑ P.J.S. van Capel a, , E. Péronne b,c, J.I. Dijkhuis a a Debye Institute for Nanomaterials Science, Center for Extreme Matter and Emergent Phenomena, Utrecht University, P.O. Box 80000, 3508 TA Utrecht, The Netherlands b CNRS, UMR 7588, Institut des NanoSciences de Paris, F-75005 Paris, France c Sorbonne Universités, UPMC Univ. Paris 06, UMR 7588, INSP, F-75005 Paris, France Pulsed femtosecond lasers can generate acoustic pulses propagating in solids while displaying either dif-fraction, attenuation, nonlinearity and/or dispersion. When acoustic attenuation and diffraction are neg-ligible, shock waves or solitons can form during propagation. Both wave types are phonon wavepackets with characteristic length scales as short as a few nanometer.
    [Show full text]
  • Picosecond Ultrasonics Study of Periodic Multilayers
    ANALYTICAL SCIENCES APRIL 2001, VOL.17 Special Issue s245 2001 © The Japan Society for Analytical Chemistry Picosecond Ultrasonics Study of Periodic Multilayers Clément Rossignol††† and Bernard Perrin Laboratoire des Milieux Désordonnés et Hétérogènes, UMR 7603 - Université Pierre & Marie Curie - CNRS T22-E4, casier 86, 4 pl. Jussieu, 75252 Paris cedex 05, France We present theoretical and experimental studies of vibrational properties of periodic multilayered structures. Experiments were performed in a series of opaque and semi-transparent superlattices, with a large range of periods, by the picosecond ultrasonics technique coupled with an interferometric setup. Acoustic pulses propagating in the whole structure and folded modes with frequencies up to 2.25 THz have been observed. The period dependence of the ratio between the respective amplitudes of low frequency and high frequency phonons is in good agreement with our theoretical model. (Received June 29, 2000; Accepted August 22, 2000) We present in this work theoretical and experimental studies perturbations induce a change ∆r(t) in the optical reflectivity of periodic multilayers by picosecond ultrasonics. An r0 of the structure. The reflection of the light probe pulse on interferometric set-up combined with a pump-probe technique, the multilayered sample gives the relative change of the based on a femtosecond laser, allows the simultaneous optical reflectivity coefficient of the perturbed structure [5] : measurement of the relative change in the amplitude and phase ∆r(t)/r0. These acoustic perturbations are probed by transient of a reflected probe pulse, induced by the acoustic field interferometric detection [2]. excited by the pump pulse [1,2]. An analytical model, allowing calculations in multilayered Theory samples has been developed.
    [Show full text]
  • 2017/ ISBN 979-11-5610-346-2 (93500) 2017 International Congress on Ultrasonics Honolulu PROGRAM
    http://www4.eng.hawaii.edu/~icu2017/ ISBN 979-11-5610-346-2 (93500) 2017 International Congress on Ultrasonics Honolulu PROGRAM Hawaii Convention Center, Honolulu, Hawaii, U.S.A. December 18 – 20, 2017 Hosted by University of Hawaii at Manoa Acoustical Society of Korea Sponsored by Acoustical Society of America Acoustical Society of China Acoustical Society of Japan International Commission for Acoustics 18 December 2017 304A 305B 306 307A 307B 308A 308B 309 Underwater Optomechanical Bubbles Acoustic Network Structures and 8:00 Fluidics Communications and Cavitation 1 and Detection Opto-acoustics Plenary 10:00 Lecture 1 Acoustic BAW and SAW Engineering Ultrasound Acoustic Nondestructive Acoustics Resonators Applications of Signal and Phononic Evaluation and 11:00 and Power Image Crystals 1 and Cells Applications Ultrasonics Processing Technology 1 Acoustic Ultrasound in Ultrasound Guided Waves Acoustic and Modeling of Industrial Elasticity Advances in and Their Elastic Sound Fields Processing Imaging and Biomedical 13:00 Applications in Metamaterials 1 in Complex and Material Biomedical Ultrasound NDE 1 Environments Engineering Applications 1 Authors’ 15:00 Workshop 19 December 2017 304A 305B 306 307A 307B 308A 308B 309 Linear and Applications of Acoustic and Nonlinear Nonlinear Novel Sensors Bubbles Life at the Ultrasound Elastic Granular Acoustics to and and Intersection of 8:00 in Air Metamaterials 2 Metamaterials Measurements Actuators Cavitation 2 Light and Sound and Devices and Imaging Plenary 10:00 Lecture 2 Reservoir Guided Waves
    [Show full text]
  • Picosecond Opto-Acoustic Interferometry and Polarimetry in High-Index Gaas
    Picosecond opto-acoustic interferometry and polarimetry in high-index GaAs A. V. Scherbakov,1* M. Bombeck,2 J. V. Jäger,2 A. S. Salasyuk,1 T. L. Linnik,3 V. E. Gusev,4 D. R. Yakovlev,1,2 A. V. Akimov,1,5 and M. Bayer1,2 1Ioffe Physical-Technical Institute, Russian Academy of Sciences, 194021 St. Petersburg, Russia 2Experimentelle Physik 2, Technische Universität Dortmund, D-44227 Dortmund, Germany 3Department of Theoretical Physics, V.E. Lashkaryov Institute of Semiconductor Physics, 03028 Kyiv, Ukraine 4IMMM, UMR-CNRS 6283, LUNAM, Université du Maine, Av. O. Messiaen, 72085 Le Mans, France 5School of Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD, UK ABSTRACT By means of a metal opto-acoustic transducer we generate quasi-longitudinal and quasi-transverse picosecond strain pulses in a (311)-GaAs substrate and monitor their propagation by picosecond acoustic interferometry. By probing at the sample side opposite to the transducer the signals related to the compressive and shear strain pulses can be separated in time. In addition to conventional monitoring of the reflected probe light intensity we monitor also the polarization rotation of the optical probe beam. This polarimetric technique results in improved sensitivity of detection and provides comprehensive information about the elasto-optical anisotropy. The experimental observations are in a good agreement with a theoretical analysis. 1. Introduction In 1984 Thomsen et al. [1,2] developed the method of generation and detection of ultrashort coherent acoustic pulses in solids by femtosecond laser excitation. Thereby the energy of a short optical pulse being absorbed in the near-surface layer of a solid medium is converted into coherent lattice vibrations.
    [Show full text]
  • Advances in Applications of Time-Domain Brillouin Scattering For
    The following article has been accepted by Applied Physics Reviews. After it is published, it will be found at https://aip.scitation.org/journal/are Advances in applications of time-domain Brillouin scattering for nanoscale imaging Vitalyi E. Gusev1,a) and Pascal Ruello2 1Laboratoire d'Acoustique de l'Université du Maine, UMR CNRS 6613, Le Mans Université, 72085 Le Mans, France a) Author to whom correspondence should be addressed. Electronic mail: [email protected] 2Institut des Molécules et Matériaux du Mans, UMR CNRS 6283, Le Mans Université, 72085 Le Mans, France Abstract Time-domain Brillouin scattering is an all-optical experimental technique based on ultrafast lasers applied for generation and detection of coherent acoustic pulses on time durations of picoseconds and length scales of nanometers. In transparent materials scattering of the probe laser beam by the coherent phonons permits imaging of sample inhomogeneity. The transient optical reflectivity of the sample recorded by the probe beam as the acoustic nanopulse propagates in space contains information on the acoustical, optical, and acousto-optical parameters of the material under study. The experimental method is based on a heterodyning where weak light pulses scattered by the coherent acoustic phonons interfere at the photodetector with probe light pulses of significantly higher amplitude reflected from various interfaces of the sample. The time-domain Brillouin scattering imaging is based on Brillouin scattering and has the potential to provide all the information that researchers in material science, physics, chemistry, biology etc., get with classic frequency-domain Brillouin scattering of light. It can be viewed as a replacement for Brillouin scattering and Brillouin microscopy in all investigations where nanoscale spatial resolution is either required or advantageous.
    [Show full text]
  • Thomas Czerniuk
    Picosecond Ultrasonics for the Modulation and Nanoscopy of Semiconductor Lasers Dissertation Zur Erlangung des akademischen Grades Doktor der Naturwissenschaften Fakultät Physik TU Dortmund Thomas Czerniuk 2017 Erster Gutachter: Prof. Manfred Bayer (Technische Universit¨atDortmund) Zweiter Gutachter: Prof. Metin Tolan (Technische Universit¨atDortmund) Dritter Gutachter: Prof. Andrey Akimov (University of Nottingham) Datum der Einreichung: 21. Juni 2017 Datum der Disputation: 18. August 2017 Contents I Introduction 5 1 Motivation and Outline 7 2 Picosecond Ultrasonics 11 2.1 Phonons . 12 2.2 Elasticity Theory . 14 2.3 Generation of Picosecond Acoustic Pulses . 16 2.4 Nonlinear Acoustic Pulse Propagation . 19 II Semiconductor Laser Emission Modulation 25 3 Vertical-Cavity-Surface-Emitting-Lasers 31 3.1 Laser Operation . 32 3.2 Laser components in VCSELs . 34 3.2.1 Microcavities and Micropillar Resonators . 34 3.2.2 Quantum Wells and Quantum Dots . 38 3.2.3 Electrical and Optical Pumping . 40 4 Picosecond Control of a Planar QD Laser 43 4.1 Semiclassical Laser Model . 44 4.2 Planar Microcavity QD Laser and Experimental Setup . 48 4.3 Measured and Simulated Laser Emission Intensity . 51 4.3.1 Positive Detuning . 51 4.3.2 Negative Detuning . 54 4.3.3 Almost Resonant Case . 55 4.3.4 Vanishing Detuning . 56 4.3.5 Evaluation of the Developed Model . 57 5 Lasing from Active Optomechanical Resonators 61 5.1 Optomechanical Resonators . 62 3 4 CONTENTS 5.2 Planar Microcavity QW Laser and Experimental Setup . 65 5.3 Experimental Results . 67 5.3.1 Emission Modulation at 180 K . 67 5.3.2 Emission Modulation at 295 K .
    [Show full text]
  • Picosecond Ultrasonic Study of Surface Acoustic Waves on Periodically 2 Patterned Layered Nanostructures
    1 Picosecond ultrasonic study of surface acoustic waves on periodically 2 patterned layered nanostructures 3 Michael Colletta,a Wanjiru Gachuhi,a Samuel A. Gartenstein,a Molly M. James,a Erik A. Szwed,a 4 Brian C. Daly,a† Weili Cui,b George A. Antonelli,c 5 a: Vassar College, 124 Raymond Ave, Poughkeepsie, NY, USA 12604 6 b: SUNY Maritime College, Throggs Neck, NY, USA 10465 7 c: Antonelli Research and Technology, 3227 SE Lambert St, Portland, OR,USA 97202 8 †: corresponding author’s email: [email protected] 9 Abstract: 10 We have used the ultrafast pump-probe technique known as picosecond ultrasonics to generate 11 and detect surface acoustic waves on a structure consisting of nanoscale Al lines on SiO2 on Si. 12 We report results from ten samples with varying pitch (1000 nm to 140 nm) and SiO2 film 13 thickness (112 nm or 60 nm), and compare our results to an isotropic elastic calculation and a 14 coarse-grained molecular dynamics simulation. In all cases we are able to detect and identify a 15 Rayleigh-like surface acoustic wave with wavelength equal to the pitch of the lines and 16 frequency in the range of 5 GHz – 24 GHz. In some samples, we are able to detect additional, 17 higher frequency surface acoustic waves or independent modes of the Al lines with frequencies 18 close to 50 GHz. We also describe the effects of probe beam polarization on the measurement’s 19 sensitivity to the different surface modes. 20 Keywords: ultrafast optics; picosecond ultrasonics; laser ultrasonics; surface acoustic waves 21 Introduction 22 The highest frequency surface acoustic waves (SAWs) have to date been generated and detected 23 by ultrafast optical pump-probe techniques.1,2,3,4 The most common method is to use lithography 24 to fabricate a nanoscale pattern of metallic lines on a substrate and excite those lines by means of 25 an ultrafast laser pulse.
    [Show full text]
  • 2001 TMS Annual Meeting & Exhibition
    Become AA TMS Member TMS derives its strength from its members, who take a hands-on approach to shaping the policy, programming, and publications of the society. Guided by these volunteers, TMS serves all segments of its professional community by: FACILITATING NETWORKING: By sponsoring numerous annual meetings and specialty conferences, TMS maximizes the opportunities for professionals from industries, universities, and government agencies worldwide to meet face to face and exchange technical ideas and experience, offer customer/client insights, find a mentor and/or serve as one, and just plain chat with peers and colleagues. PRODUCING JOM AND OTHER PUBLICATIONS: Every TMS member receives a complimentary subscription to JOM. Formerly Journal of Metals, this highly respected monthly journal, explores traditional, innovative, and revolutionary issues in the minerals, metals, and materials fields. Designed to be of maximum and immediate benefit to readers throughout the world, JOM is on-line before the print version is mailed. TMS also publishes three other journals (Journal of Electronic Materials and Metallurgical and Materials Transactions A and B), numerous conference proceedings volumes and textbooks, and videos designed to give materials scientists and engi- neers the latest information on scientific and applied advances in areas as diverse as electronic materials, automotive manu- facture, and extractive metallurgy. PROMOTING LIFE-LONG LEARNING: TMS is dedicated to the education of the materials science and engineering professional as well as to cultivating an interest in the field by young people. For the practicing professional, TMS and its five technical divisions sponsor continuing education courses, primarily technical but also nontechnical, to promote the education and development of current and future professionals.
    [Show full text]
  • Picosecond Ultrasonics with a Free-Running Dual-Comb Laser
    Picosecond ultrasonics with a free-running dual-comb laser JUSTINAS PUPEIKIS,1,* BENJAMIN WILLENBERG,1 FRANCOIS BRUNO,2 MIKE HETTICH,3 ALEXANDER NUSSBAUM-LAPPING,1 MATTHIAS GOLLING,1 CAROLIN P. BAUER,1 SANDRO L. CAMENZIND,1 ABDELMJID BENAYAD,4 PATRICE CAMY,4 BERTRAND AUDOIN,2 CHRISTOPHER R. PHILLIPS,1 AND URSULA KELLER1 1Department of Physics, Institute for Quantum Electronics, ETH Zurich, Switzerland 2Univ. Bordeaux, CNRS, I2M, UMR 5295, F-33400 Talence, France 3Research Center for Non-Destructive Testing GmbH, 4040 Linz, Austria 4Centre de Recherche sur Les Ions, Les Matériaux et La Photonique (CIMAP), UMR 6252 CEA-CNRS- ENSICAEN, Université de Caen Normandie, 6 Boulevard Du Maréchal Juin, 14050, Caen Cedex 4, France *[email protected] Abstract: We present a free-running 80-MHz dual-comb polarization-multiplexed solid-state laser which delivers 1.8 W of average power with 110-fs pulse duration per comb. With a high- sensitivity pump-probe setup, we apply this free-running dual-comb laser to picosecond ultrasonic measurements. The ultrasonic signatures in a semiconductor multi-quantum-well structure originating from the quantum wells and superlattice regions are revealed and discussed. We further demonstrate ultrasonic measurements on a thin-film metalized sample and compare these measurements to ones obtained with a pair of locked femtosecond lasers. Our data show that a free-running dual-comb laser is well-suited for picosecond ultrasonic measurements and thus it offers a significant reduction in complexity and cost for this widely adopted non-destructive testing technique. © 2021 Optical Society of America under the terms of the OSA Open Access Publishing Agreement 1.
    [Show full text]
  • High Resolution 3D Imaging of Living Cells with Sub-Optical Wavelength Phonons Received: 15 July 2016 Fernando Pérez-Cota, Richard J
    www.nature.com/scientificreports OPEN High resolution 3D imaging of living cells with sub-optical wavelength phonons Received: 15 July 2016 Fernando Pérez-Cota, Richard J. Smith, Emilia Moradi, Leonel Marques, Kevin F. Webb & Accepted: 22 November 2016 Matt Clark Published: 20 December 2016 Label-free imaging of living cells below the optical diffraction limit poses great challenges for optical microscopy. Biologically relevant structural information remains below the Rayleigh limit and beyond the reach of conventional microscopes. Super-resolution techniques are typically based on the non- linear and stochastic response of fluorescent labels which can be toxic and interfere with cell function. In this paper we present, for the first time, imaging of live cells using sub-optical wavelength phonons. The axial imaging resolution of our system is determined by the acoustic wavelength (λa = λprobe/2n) and not on the NA of the optics allowing sub-optical wavelength acoustic sectioning of samples using the time of flight. The transverse resolution is currently limited to the optical spot size. The contrast mechanism is significantly determined by the mechanical properties of the cells and requires no additional contrast agent, stain or label to image the cell structure. The ability to breach the optical diffraction limit to image living cells acoustically promises to bring a new suite of imaging technologies to bear in answering exigent questions in cell biology and biomedicine. Optical microscopy is possibly the most powerful technique used in the life sciences to study cell biology and remains an extremely active global research area, continuing to drive advances in biomedicine. Imaging of live cells is crucial in order to study structure, function and dynamic behaviour – often a difficult problem because of the scale, fragility, and weak optical contrast of living cells.
    [Show full text]
  • Picosecond Ultrasonics: a Technique Destined for BAW Technology
    1st International Symposium on Laser Ultrasonics: Science, Technology and Applications July 16-18 2008, Montreal, Canada Picosecond Ultrasonics: a Technique Destined for BAW Technology Patrick EMERY 1, Arnaud DEVOS 1, Pascal ANCEY 2 1 Institut d’Électronique, de Microélectronique et de Nanotechnologie, Unité Mixte de Recherche CNRS 8250, BP 69, Avenue Poincaré, F-59652 Villeneuve d’Ascq Cedex, France e-mail: [email protected] , [email protected] , 2 ST Microelectronics, 850 rue Jean Monnet, F-38926 Crolles Cedex, France e-mail: [email protected] Abstract Since the 80’s, Bulk Acoustic Wave (BAW) resonators technology has been seeing a rapid expansion, due to its potentials in terms of performances and integration for Radio-Frequency (RF) filtering. The control of the frequency is a challenging question for the mass production of such devices, and passes through an accurate control of mechanical properties of the whole stack. The picosecond ultrasonics technique is well-suited for the characterization of such a component. Using a colored setup (i.e. various probe wavelengths), it allows the measurement of several acoustic parameters (longitudinal acoustic phonon velocity, density, acoustic attenuation, thermal expansion and temperature dependence of sound velocity) of complex thin films stacks. Moreover, picosecond ultrasonics is prepared for on product process control measurements, and fits the requirements of a metrological support for BAW production. Keywords: BAW resonators, Picosecond ultrasonics, elastic constant, thin films, trimming 1. Introduction In the current wireless systems, most of the functions are performed by microelectronic components fabricated on silicon or gallium arsenide. However, radio frequency (RF) and intermediate frequency (IF) filters are usually surface acoustic wave (SAW) components, which are not compatible with CMOS or BiCMOS process.
    [Show full text]
  • Picosecond Acoustics Technique to Measure the Sound Velocities of Fe-Si Alloys and Si Single-Crystals at High Pressure
    minerals Article Picosecond Acoustics Technique to Measure the Sound Velocities of Fe-Si Alloys and Si Single-Crystals at High Pressure Eric Edmund † , Michel Gauthier, Daniele Antonangeli, Simon Ayrinhac, Silvia Boccato, Thibault Deletang, Marc Morand, Yiuri Garino , Paraskevas Parisiades and Frédéric Decremps * Institut de Minéralogie de Physique des Matériaux et de Cosmochimie, Sorbonne Université— CNRS—Muséum National d’Histoire Naturelle, 4 Place Jussieu, F-75005 Paris, France; [email protected] (E.E.); [email protected] (M.G.); [email protected] (D.A.); [email protected] (S.A.); [email protected] (S.B.); [email protected] (T.D.); [email protected] (M.M.); [email protected] (Y.G.); [email protected] (P.P.) * Correspondence: [email protected] † Current address: Center for High Pressure Science and Technology Advanced Research (HPSTAR), Shanghai 201203, China. Received: 23 January 2020; Accepted: 19 February 2020 ; Published: 27 February 2020 Abstract: We describe here a time resolved pump-probe laser technique—picosecond interferometry—which has been combined with diamond anvil cells (DAC). This method enables the measurement of the longitudinal sound velocity up to Mbar pressure for any kind of material (solids, liquids, metals, insulators). We also provide a description of picosecond acoustics data analysis in order to determine the complete set of elastic constants for single crystals. To illustrate such capabilities, results are given on the pressure dependence of the acoustic properties for prototypical cases: polycrystal (hcp-Fe-5 wt% Si up to 115 GPa) and single-crystal (Si up to 10 GPa).
    [Show full text]