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Noll F, Krauß N, Gusev V, Dekorsy T, Hettich M. Surface plasmon-based detection for picosecond ultrasonics in planar gold-dielectric layer geometries. Photoacoustics 2023; 30:100464. [PMID: 36936710 PMCID: PMC10017422 DOI: 10.1016/j.pacs.2023.100464] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/15/2022] [Revised: 02/03/2023] [Accepted: 02/21/2023] [Indexed: 06/18/2023]
Abstract
Longitudinal acoustic modes in planar thin gold films are excited and detected by a combination of ultrafast pump-probe photoacoustic spectroscopy and a surface plasmon resonance (SPR) technique. The resulting high sensitivity allows the detection of acoustic modes up to the 7th harmonic (258 GHz) with sub-pm amplitude sensing capabilities. This makes a comparison of damping times of individual modes possible. Further, the dynamics of the real and imaginary part of the dielectric function and the film's thickness variation are separated by using the dependence of the amplitudes of the acoustic modes on the detection angle and the surface plasmon resonance. We find that longitudinal acoustic modes in the gold films mainly affect the real part of the dielectric function and highlight the importance to consider thickness related effects in acousto-plasmonic sensing.
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Affiliation(s)
- F. Noll
- Department of Physics, University of Konstanz, 78464 Konstanz, Germany
- Research Center for Non-Destructive Testing GmbH (RECENDT), Altenbergerstr. 69, 4040 Linz, Austria
| | - N. Krauß
- Department of Physics, University of Konstanz, 78464 Konstanz, Germany
| | - V. Gusev
- Laboratoire d′Acoustique de l′Université du Mans (LAUM), UMR 6613, Institut d′Acoustique - Graduate School (IA-GS), CNRS, Le Mans Université, Av. O. Messiaen, 72085 Le Mans, France
| | - T. Dekorsy
- Department of Physics, University of Konstanz, 78464 Konstanz, Germany
- Institute of Technical Physics, German Aerospace Center, Pfaffenwaldring 38-40, 70569 Stuttgart, Germany
| | - M. Hettich
- Department of Physics, University of Konstanz, 78464 Konstanz, Germany
- Research Center for Non-Destructive Testing GmbH (RECENDT), Altenbergerstr. 69, 4040 Linz, Austria
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Brick D, Hofstetter M, Stritt P, Rinder J, Gusev V, Dekorsy T, Hettich M. Glass transition of nanometric polymer films probed by picosecond ultrasonics. Ultrasonics 2022; 119:106630. [PMID: 34735929 DOI: 10.1016/j.ultras.2021.106630] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/03/2020] [Revised: 08/14/2021] [Accepted: 10/17/2021] [Indexed: 06/13/2023]
Abstract
The possibility to measure the glass transition temperature in poly(methyl methacrylate) (PMMA) films by picosecond ultrasonics with thicknesses ranging from 458 nm to 32 nm is demonstrated. A shift of the longitudinal acoustic eigenmodes towards lower frequencies with temperature is observed accompanied by a change in the temperature-frequency slopes at the glass transition temperature. The contributions to the frequency shift from changes in film thickness and sound velocity are discussed and the latter is extracted below the glass transition temperature. Finally, the advantages and disadvantages of the current approach in a comparison to other methods based on acoustic measurements in the GHz regime are reviewed.
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Affiliation(s)
- D Brick
- Department of Physics, University of Konstanz, 78464 Konstanz, Germany
| | - M Hofstetter
- Department of Physics, University of Konstanz, 78464 Konstanz, Germany
| | - P Stritt
- Department of Physics, University of Konstanz, 78464 Konstanz, Germany
| | - J Rinder
- Department of Physics, University of Konstanz, 78464 Konstanz, Germany
| | - V Gusev
- Laboratoire d'Acoustique de l'Université du Mans (LAUM), UMR 6613, Institut d'Acoustique - Graduate School (IA-GS), CNRS, Le Mans Université, Av. O. Messiaen, 72085 Le Mans, France
| | - T Dekorsy
- Department of Physics, University of Konstanz, 78464 Konstanz, Germany; Institute of Technical Physics, German Aerospace Center, Pfaffenwaldring 38-40, 70569 Stuttgart, Germany
| | - M Hettich
- Department of Physics, University of Konstanz, 78464 Konstanz, Germany; Research Center for Non-Destructive Testing GmbH, Altenbergerstr. 96, 4040 Linz, Austria..
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3
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Li C, Gusev V, Dekorsy T, Hettich M. All optical control of comb-like coherent acoustic phonons in multiple quantum well structures through double-pump-pulse pump-probe experiments. Opt Express 2019; 27:18706-18730. [PMID: 31252809 DOI: 10.1364/oe.27.018706] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/12/2019] [Accepted: 05/30/2019] [Indexed: 06/09/2023]
Abstract
We present an advancement in applications of ultrafast optics in picosecond laser ultrasonics - laser-induced comb-like coherent acoustic phonons are optically controlled in a In0.27Ga0.73As/GaAs multiple quantum well (MQW) structure by a high-speed asynchronous optical sampling (ASOPS) system based on two GHz Yb:KYW lasers. Two successive pulses from the same pump laser are used to excite the MQW structure. The second pump light pulse has a tunable time delay with respect to the first one and can be also tuned in intensity, which enables the amplitude and phase modulation of acoustic phonons. This yields rich temporal acoustic patterns with suppressed or enhanced amplitudes, various wave-packet shapes, varied wave-packet widths, reduced wave-packet periods and varied phase shifts of single-period oscillations within a wave-packet. In the frequency domain, the amplitude and phase shift of the individual comb component present a second-pump-delay-dependent cosine-wave-like and sawtooth-wave-like variation, respectively, with a modulation frequency equal to the comb component frequency itself. The variations of the individual component amplitude and phase shift by tuning the second pump intensity exhibit an amplitude valley and an abrupt phase jump at the ratio around 1:1 of the two pump pulse intensities for certain time delays. A simplified model, where both generation and detection functions are assumed as a cosine stress wave enveloped by Gaussian or rectangular shapes in an infinite periodic MQW structure, is developed in order to interpret acoustic manipulation in the MQW sample. The modelling agrees well with the experiment in a wide range of time delays and intensity ratios. Moreover, by applying a heuristic-analytical approach and nonlinear corrections, the improved calculations reach an excellent agreement with experimental results and thus enable to predict and synthesize coherent acoustic wave patterns in MQW structures.
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Brick D, Engemaier V, Guo Y, Grossmann M, Li G, Grimm D, Schmidt OG, Schubert M, Gusev VE, Hettich M, Dekorsy T. Interface Adhesion and Structural Characterization of Rolled-up GaAs/In 0.2Ga 0.8As Multilayer Tubes by Coherent Phonon Spectroscopy. Sci Rep 2017; 7:5385. [PMID: 28710450 PMCID: PMC5511180 DOI: 10.1038/s41598-017-05739-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2017] [Accepted: 06/01/2017] [Indexed: 12/02/2022] Open
Abstract
We present a detailed experimental and theoretical study of the acoustic phonon modes in rolled-up multilayers with thickness of the layers in the nanometre and diameters in the micrometre range. We compare our results to planar, unrolled multilayers grown by molecular beam epitaxy. For the planar multilayers the experimentally obtained acoustic modes exhibit properties of a superlattice and match well to calculations obtained by the Rytov model. The rolled-up superlattice tubes show intriguing differences compared to the planar structures which can be attributed to the imperfect adhesion between individual tube windings. A transfer matrix method including a massless spring accounting for the imperfect adhesion between the layers yields good agreement between experiment and calculations for up to five windings. Areas with sufficient mechanical coupling between all windings can be distinguished by their acoustic mode spectrum from areas where individual windings are only partially in contact. This allows the spatially resolved characterization of individual tubes with micrometre spatial resolution where areas with varying interface adhesion can be identified.
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Affiliation(s)
- D Brick
- Department of Physics, University of Konstanz, 78464, Konstanz, Germany.
| | - V Engemaier
- Institute for Integrative Nanosciences, IFW Dresden, Helmholtzstrasse 20, 01069, Dresden, Germany
| | - Y Guo
- Department of Physics, University of Konstanz, 78464, Konstanz, Germany
| | - M Grossmann
- Department of Physics, University of Konstanz, 78464, Konstanz, Germany
| | - G Li
- Institute for Integrative Nanosciences, IFW Dresden, Helmholtzstrasse 20, 01069, Dresden, Germany
| | - D Grimm
- Institute for Integrative Nanosciences, IFW Dresden, Helmholtzstrasse 20, 01069, Dresden, Germany
| | - O G Schmidt
- Institute for Integrative Nanosciences, IFW Dresden, Helmholtzstrasse 20, 01069, Dresden, Germany
| | - M Schubert
- Department of Physics, University of Konstanz, 78464, Konstanz, Germany
| | - V E Gusev
- LAUM, UMR-CNRS 6613, Université du Maine, Av. O. Messiaen, 72085, Le Mans, France
| | - M Hettich
- Department of Physics, University of Konstanz, 78464, Konstanz, Germany
| | - T Dekorsy
- Department of Physics, University of Konstanz, 78464, Konstanz, Germany.,Institute of Technical Physics, German Aerospace Center, Pfaffenwaldring 38-40, 70569, Stuttgart, Germany
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5
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Li C, Krauß N, Schäfer G, Ebner L, Kliebisch O, Schmidt J, Winnerl S, Hettich M, Dekorsy T. High-speed asynchronous optical sampling based on GHz Yb:KYW oscillators. Opt Express 2017; 25:9204-9212. [PMID: 28437994 DOI: 10.1364/oe.25.009204] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
A low-cost scheme of high-speed asynchronous optical sampling based on Yb:KYW oscillators is reported. Two GHz diode-pumped oscillators with a slight pulse repetition rate offset serve as pump and probe source, respectively. The temporal resolution of this system is limited to 500 fs mainly by the pulse duration of the oscillators and also by relative timing jitter between the oscillators. A near-shot-noise noise floor around 10-6 (∆R/R) is obtained within a data acquisition time of a few seconds. The performance of the system is demonstrated by measurements of coherent acoustic phonons in a semiconductor sample that resembles a semiconductor saturable absorber mirror or an optically pumped semiconductor chip.
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Luan C, Yang K, Zhao J, Zhao S, Li T, Zhang H, He J, Song L, Dekorsy T, Guina M, Zheng L. Diode-pumped mode-locked Tm:LuAG laser at 2 μm based on GaSb-SESAM. Opt Lett 2017; 42:839-842. [PMID: 28198878 DOI: 10.1364/ol.42.000839] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Mode-locking of a directly diode-pumped Tm:LuAG laser is demonstrated using GaSb-based semiconductor saturable absorber mirrors (SESAMs). Stable and self-starting mode-locked operation was realized, generating pulses as short as 13.6 ps at 2024 nm with a maximum output power of 98 mW. Two GaInAs-based SESAMs were used for comparison with the operation based upon the use of the GaSb SESAM; in this case, longer pulses with durations of 27 ps and 34 ps were obtained under the same experimental conditions. Our work sets a new record in pulse duration for mode-locked Tm:LuAG lasers and confirms that lattice-matched GaSb-based SESAMs are beneficial for mode-locked solid-state lasers in the 2 μm range.
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Schubert M, Schaefer H, Mayer J, Laptev A, Hettich M, Merklein M, He C, Rummel C, Ristow O, Großmann M, Luo Y, Gusev V, Samwer K, Fonin M, Dekorsy T, Demsar J. Collective Modes and Structural Modulation in Ni-Mn-Ga(Co) Martensite Thin Films Probed by Femtosecond Spectroscopy and Scanning Tunneling Microscopy. Phys Rev Lett 2015; 115:076402. [PMID: 26317735 DOI: 10.1103/physrevlett.115.076402] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2015] [Indexed: 06/04/2023]
Abstract
The origin of the martensitic transition in the magnetic shape memory alloy Ni-Mn-Ga has been widely discussed. While several studies suggest it is electronically driven, the adaptive martensite model reproduced the peculiar nonharmonic lattice modulation. We used femtosecond spectroscopy to probe the temperature and doping dependence of collective modes, and scanning tunneling microscopy revealed the corresponding static modulations. We show that the martensitic phase can be described by a complex charge-density wave tuned by magnetic ordering and strong electron-lattice coupling.
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Affiliation(s)
- M Schubert
- Department of Physics, University of Konstanz, 78457 Konstanz, Germany
| | - H Schaefer
- Department of Physics, University of Konstanz, 78457 Konstanz, Germany
- Institute of Physics, Ilmenau University of Technology, 98693 Ilmenau, Germany
| | - J Mayer
- Department of Physics, University of Konstanz, 78457 Konstanz, Germany
| | - A Laptev
- Department of Physics, University of Konstanz, 78457 Konstanz, Germany
| | - M Hettich
- Department of Physics, University of Konstanz, 78457 Konstanz, Germany
| | - M Merklein
- Department of Physics, University of Konstanz, 78457 Konstanz, Germany
| | - C He
- Department of Physics, University of Konstanz, 78457 Konstanz, Germany
| | - C Rummel
- Department of Physics, University of Konstanz, 78457 Konstanz, Germany
| | - O Ristow
- Department of Physics, University of Konstanz, 78457 Konstanz, Germany
| | - M Großmann
- Department of Physics, University of Konstanz, 78457 Konstanz, Germany
| | - Y Luo
- I. Physikalisches Institut, Georg-August-Universität Göttingen, 37073 Göttingen, Germany
| | - V Gusev
- Department of Physics, University of Konstanz, 78457 Konstanz, Germany
- Laboratoire d'Acoustique, LAUM, UMR CNRS 6613, LUNAM Université, Université du Maine, 72085 Le Mans, France
| | - K Samwer
- I. Physikalisches Institut, Georg-August-Universität Göttingen, 37073 Göttingen, Germany
| | - M Fonin
- Department of Physics, University of Konstanz, 78457 Konstanz, Germany
| | - T Dekorsy
- Department of Physics, University of Konstanz, 78457 Konstanz, Germany
| | - J Demsar
- Department of Physics, University of Konstanz, 78457 Konstanz, Germany
- Institute of Physics, Ilmenau University of Technology, 98693 Ilmenau, Germany
- Institute of Physics, Johannes Gutenberg-University Mainz, 55128 Mainz, Germany
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8
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Krauß N, Schäfer G, Flock J, Kliebisch O, Li C, Barros HG, Heinecke DC, Dekorsy T. Two-colour high-speed asynchronous optical sampling based on offset-stabilized Yb:KYW and Ti:sapphire oscillators. Opt Express 2015; 23:18288-18299. [PMID: 26191885 DOI: 10.1364/oe.23.018288] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
We present a high-speed asynchronous optical sampling system, based on two different Kerr-lens mode-locked lasers with a GHz repetition rate: An Yb:KYW oscillator and a Ti:sapphire oscillator are synchronized in a master-slave configuration at a repetition rate offset of a few kHz. This system enables two-colour pump-probe measurements with resulting noise floors below 10⁻⁶ at a data aquisition time of 5 seconds. The measured temporal resolution within the 1 ns time window is below 350 fs, including a timing jitter of less than 50 fs. The system is applied to investigate zone-folded coherent acoustic phonons in two different semiconductor superlattices in transmission geometry at a probe wavelength far below the bandgap of the superlattice constituents. The lifetime of the phonon modes with a zero wave vector and frequencies in the range from 100 GHz to 500 GHz are measured at room temperature and compared with previous work.
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Feng T, Yang K, Zhao J, Zhao S, Qiao W, Li T, Dekorsy T, He J, Zheng L, Wang Q, Xu X, Su L, Xu J. 1.21 W passively mode-locked Tm:LuAG laser. Opt Express 2015; 23:11819-11825. [PMID: 25969273 DOI: 10.1364/oe.23.011819] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
A watt-level output passively mode-locked Tm:LuAG bulk laser with an InGaAs semiconductor saturable absorber mirror (SESAM) is demonstrated for the first time. A maximum average output power of 1.21 W at 2022.9 nm has been achieved with a pulse duration of 38 ps and a repetition rate of 129.2 MHz. The results indicate the potential of Tm:LuAG crystals as candidate for realizing high power ultrafast lasers at 2 μm.
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Krauss N, Nast A, Heinecke DC, Kölbl C, Barros HG, Dekorsy T. Fiber-coupled high-speed asynchronous optical sampling with sub-50 fs time resolution. Opt Express 2015; 23:2145-2156. [PMID: 25836085 DOI: 10.1364/oe.23.002145] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
We present a fiber-coupled pump-probe system with a sub-50 fs time resolution and a nanosecond time window, based on high-speed asynchronous optical sampling. By use of a transmission grism pulse compressor, we achieve pump pulses with a pulse duration of 42 fs, an average power of 300 mW and a peak power exceeding 5 kW at a pulse repetition rate of 1 GHz after 6 m of optical fiber. With this system we demonstrate thickness mapping of soft X-ray mirrors at a sub-nm thickness resolution on a cm(2) scan area. In addition, terahertz field generation with resolved spectral components of up to 3.5 THz at a GHz frequency resolution is demonstrated.
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Fleischhaker R, Krauss N, Schättiger F, Dekorsy T. Consistent characterization of semiconductor saturable absorber mirrors with single-pulse and pump-probe spectroscopy. Opt Express 2013; 21:6764-6776. [PMID: 23546059 DOI: 10.1364/oe.21.006764] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
We study the comparability of the two most important measurement methods used for the characterization of semiconductor saturable absorber mirrors (SESAMs). For both methods, single-pulse spectroscopy (SPS) and pump-probe spectroscopy (PPS), we analyze in detail the time-dependent saturation dynamics inside a SESAM. Based on this analysis, we find that fluence-dependent PPS at complete spatial overlap and zero time delay is equivalent to SPS. We confirm our findings experimentally by comparing data from SPS and PPS of two samples. We show how to interpret this data consistently and we give explanations for possible deviations.
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Affiliation(s)
- R Fleischhaker
- Center for Applied Photonics and Department of Physics, University of Konstanz, Box M700, 78457 Konstanz, Germany.
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12
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Cuffe J, Ristow O, Chávez E, Shchepetov A, Chapuis PO, Alzina F, Hettich M, Prunnila M, Ahopelto J, Dekorsy T, Sotomayor Torres CM. Lifetimes of confined acoustic phonons in ultrathin silicon membranes. Phys Rev Lett 2013; 110:095503. [PMID: 23496722 DOI: 10.1103/physrevlett.110.095503] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/27/2012] [Indexed: 06/01/2023]
Abstract
We study the relaxation of coherent acoustic phonon modes with frequencies up to 500 GHz in ultrathin free-standing silicon membranes. Using an ultrafast pump-probe technique of asynchronous optical sampling, we observe that the decay time of the first-order dilatational mode decreases significantly from ~4.7 ns to 5 ps with decreasing membrane thickness from ~194 to 8 nm. The experimental results are compared with theories considering both intrinsic phonon-phonon interactions and extrinsic surface roughness scattering including a wavelength-dependent specularity. Our results provide insight to understand some of the limits of nanomechanical resonators and thermal transport in nanostructures.
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Affiliation(s)
- J Cuffe
- Catalan Institute of Nanotechnology (ICN2), Campus UAB, 08193 Bellaterra (Barcelona), Spain.
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Yang KJ, Heinecke DC, Kölbl C, Dekorsy T, Zhao SZ, Zheng LH, Xu J, Zhao GJ. Mode-locked Tm,Ho:YAP laser around 2.1 μm. Opt Express 2013; 21:1574-1580. [PMID: 23389141 DOI: 10.1364/oe.21.001574] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
A passively mode-locked Tm,Ho:YAP laser around 2.1 μm wavelength employing a semiconductor saturable absorber mirror is demonstrated. Stable continuous wave mode-locking operation was achieved at variable center wavelengths of 2036.5 nm, 2064.5 nm, 2095.5 nm, 2103.5 nm, and 2130 nm, respectively. Pulses as short as 40.4 ps were obtained at 2064.5 nm with a spectral FWHM of 0.5 nm at output powers of 132 mW and a repetition rate around 107 MHz. A maximum output power of 238 mW was obtained at 2130 nm with a pulse duration of 66 ps.
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Affiliation(s)
- K J Yang
- Department of Physics and Center of Applied Photonics, University of Konstanz, 78457 Konstanz, Germany.
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14
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Qiao W, Stephan D, Hasselbeck M, Liang Q, Dekorsy T. Low-temperature THz time domain waveguide spectrometer with butt-coupled emitter and detector crystal. Opt Express 2012; 20:19769-19777. [PMID: 23037029 DOI: 10.1364/oe.20.019769] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
A compact high-resolution THz time-domain waveguide spectrometer that is operated inside a cryostat is demonstrated. A THz photo-Dember emitter and a ZnTe electro-optic detection crystal are directly attached to a parallel copper-plate waveguide. This allows the THz beam to be excited and detected entirely inside the cryostat, obviating the need for THz-transparent windows or external THz mirrors. Since no external bias for the emitter is required, no electric feed-through into the cryostat is necessary. Using asynchronous optical sampling, high resolution THz spectra are obtained in the frequency range from 0.2 to 2.0 THz. The THz emission from the photo-Dember emitter and the absorption spectrum of 1,2-dicyanobenzene film are measured as a function of temperature. An absorption peak around 750 GHz of 1,2-dicyanobenzene displays a blue shift with increasing temperature.
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Affiliation(s)
- W Qiao
- Department of Physics and Center for Applied Photonics, University of Konstanz, D-78457 Konstanz, Germany
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15
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Yang KJ, Bromberger H, Heinecke D, Kölbl C, Schäfer H, Dekorsy T, Zhao SZ, Zheng LH, Xu J, Zhao GJ. Efficient continuous wave and passively mode-locked Tm-doped crystalline silicate laser. Opt Express 2012; 20:18630-18635. [PMID: 23038503 DOI: 10.1364/oe.20.018630] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
An efficient continuous wave and passively mode-locked thulium-doped oxyorthosilicate Tm:LuYSiO5 laser is demonstrated. A maximum slope efficiency of 56.3% is obtained at 2057.4 nm in continuous wave operation regime. With an InGaAs quantum well SESAM, self-starting passively mode-locked Tm:LuYSiO5 laser is realized in the 1929 nm to 2065 nm spectral region. A maximum average output power of 130.2 mW with a pulse duration of 33.1 ps and a repetition rate of about 100 MHz is generated at 1984.1 nm. Pulses as short as 24.2 ps with an average output power of 100 mW are obtained with silicon prisms where used to manage the intracavity dispersion. The shortest pulse duration of about 19.6 ps is obtained with an average output power of 64.5 mW at 1944.3 nm.
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Affiliation(s)
- K J Yang
- Department of Physics and Center of Applied Photonics, University of Konstanz, 78457 Konstanz, Germany.
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16
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Bromberger H, Yang KJ, Heinecke D, Dekorsy T, Zheng LH, Xu J, Zhao GJ. Comparative investigations on continuous wave operation of a-cut and b-cut Tm,Ho:YAlO3 lasers at room temperature. Opt Express 2011; 19:6505-6513. [PMID: 21451679 DOI: 10.1364/oe.19.006505] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
The Tm,Ho:YAlO3 laser performance for two crystal orientations pumped by a wavelength tunable Ti:Sapphire laser is presented in this paper. An experimental investigation comparing a- and b-oriented Tm,Ho:YAlO3 crystals laser performance is demonstrated and discussed. Single- and multi-wavelength operations of Tm,Ho:YAlO3 lasers have been investigated in detail. The maximum output powers of 890 mW at 2119 nm for a-oriented Tm,Ho:YAlO3 crystal and 946 mW at 2103 nm for b-oriented Tm,Ho:YAlO3 crystal have been obtained, respectively. The two crystals show very similar performance in terms of output power and conversion efficiency, only that the b-cut Tm,Ho:YAP crystal demonstrates more regimes of multi-wavelength operations.
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Affiliation(s)
- H Bromberger
- Department of Physics and Center of Applied Photonics, University of Konstanz, Konstanz, Germany
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17
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Bruchhausen A, Gebs R, Hudert F, Issenmann D, Klatt G, Bartels A, Schecker O, Waitz R, Erbe A, Scheer E, Huntzinger JR, Mlayah A, Dekorsy T. Subharmonic resonant optical excitation of confined acoustic modes in a free-standing semiconductor membrane at GHz frequencies with a high-repetition-rate femtosecond laser. Phys Rev Lett 2011; 106:077401. [PMID: 21405540 DOI: 10.1103/physrevlett.106.077401] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/09/2010] [Indexed: 05/30/2023]
Abstract
We propose subharmonic resonant optical excitation with femtosecond lasers as a new method for the characterization of phononic and nanomechanical systems in the gigahertz to terahertz frequency range. This method is applied for the investigation of confined acoustic modes in a free-standing semiconductor membrane. By tuning the repetition rate of a femtosecond laser through a subharmonic of a mechanical resonance we amplify the mechanical amplitude, directly measure the linewidth with megahertz resolution, infer the lifetime of the coherently excited vibrational states, accurately determine the system's quality factor, and determine the amplitude of the mechanical motion with femtometer resolution.
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Affiliation(s)
- A Bruchhausen
- Department of Physics & Center for Applied Photonics, Universität Konstanz, Germany
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18
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Beck M, Schäfer H, Klatt G, Demsar J, Winnerl S, Helm M, Dekorsy T. Impulsive terahertz radiation with high electric fields from an amplifier-driven large-area photoconductive antenna. Opt Express 2010; 18:9251-9257. [PMID: 20588772 DOI: 10.1364/oe.18.009251] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
We report on the generation of impulsive terahertz (THz) radiation with 36 kV/cm vacuum electric field (1.5 mW average thermal power) at 250 kHz repetition rate and a high NIR-to-THz conversion efficiency of 2 x 10(-3). This is achieved by photoexciting biased large-area photoconductive emitter with NIR fs pulses of microJ pulse energy. We demonstrate focussing of the THz beam by tailoring the pulse front of the exciting laser beam without any focussing element for the THz beam. A high dynamic range of 10(4) signal-to-noise is obtained with an amplifier based system.
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Affiliation(s)
- M Beck
- Department of Physics and Center for Applied Photonics, University of Konstanz, D-78457 Konstanz, Germany.
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19
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Abstract
We report an ultrafast time-domain spectroscopy system based on high-speed asynchronous optical sampling operating without mechanical scanner. The system uses two 1 GHz femtosecond oscillators that are offset-stabilized using high-bandwidth feedback electronics operating at the tenth repetition rate harmonics. Definition of the offset frequency, i.e. the time-delay scan rate, in the range of a few kilohertz is accomplished using direct-digital-synthesis electronics for the first time. The time-resolution of the system over the full available 1 ns time-delay window is determined by the laser pulse duration and is 45 fs. This represents a three-fold improvement compared to previous approaches where timing jitter was the limiting factor. Two showcase experiments are presented to verify the high time-resolution and sensitivity of the system.
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Affiliation(s)
- R Gebs
- Department of Physics and Center for Applied Photonics, University of Konstanz, D-78457, Germany.
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20
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Klatt G, Hilser F, Qiao W, Beck M, Gebs R, Bartels A, Huska K, Lemmer U, Bastian G, Johnston MB, Fischer M, Faist J, Dekorsy T. Terahertz emission from lateral photo-Dember currents. Opt Express 2010; 18:4939-47. [PMID: 20389505 DOI: 10.1364/oe.18.004939] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
The photo-Dember effect is a source of impulsive THz emission following femtosecond pulsed optical excitation. This emission results from the ultrafast spatial separation of electron-hole pairs in strong carrier gradients due to their different diffusion coefficients. The associated time dependent polarization is oriented perpendicular to the excited surface which is inaptly for efficient out coupling of THz radiation. We propose a scheme for generating strong carrier gradients parallel to the excited surface. The resulting photo-Dember currents are oriented in the same direction and emit THz radiation into the favorable direction perpendicular to the surface. This effect is demonstrated for GaAs and In(0.53)Ga(0.47)As. Surprisingly the photo-Dember THz emitters provide higher bandwidth than photoconductive emitters. Multiplexing of phase coherent photo-Dember currents by periodically tailoring the photoexcited spatial carrier distribution gives rise to a strongly enhanced THz emission, which reaches electric field amplitudes comparable to a high-efficiency externally biased photoconductive emitter.
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Affiliation(s)
- G Klatt
- Department of Physics and Center for Applied Photonics, University of Konstanz 78457, Germany
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21
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Klatt G, Gebs R, Janke C, Dekorsy T, Bartels A. Rapid-scanning terahertz precision spectrometer with more than 6 THz spectral coverage. Opt Express 2009; 17:22847-22854. [PMID: 20052210 DOI: 10.1364/oe.17.022847] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
We report a terahertz time-domain spectrometer with more than 6 THz spectral coverage and 1 GHz resolution based on high-speed asynchronous optical sampling. It operates at 2 kHz scan rate without mechanical delay stage. The frequency error of the system at 60 s acquisition time is determined by comparing a measured water vapor absorption spectrum to data reported in the HITRAN database. The mean error of 87 evaluated absorption lines is 142 MHz.
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Affiliation(s)
- G Klatt
- Department of Physics and Center for Applied Photonics, University of Konstanz, D-78457, Germany.
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22
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Gebs R, Dekorsy T, Diddams SA, Bartels A. 1-GHz repetition rate femtosecond OPO with stabilized offset between signal and idler frequency combs. Opt Express 2008; 16:5397-5405. [PMID: 18542642 DOI: 10.1364/oe.16.005397] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
We report an optical parametric oscillator (OPO) based on periodically poled lithium niobate (PPLN) that is synchronously pumped by a femtosecond Ti:sapphire laser at 1 GHz repetition rate. The signal output has a center wavelength of 1558 nm and its spectral bandwidth amounts to 40 nm. The OPO operates in a regime where the signal- and idler frequency combs exhibit a partial overlap around 1600 nm. In this near-degeneracy region, a beat at the offset between the signal and idler frequency combs is detected. Phase-locking this beat to an external reference stabilizes the spectral envelopes of the signal- and idler output. At the same time, the underlying frequency combs are stabilized relative to each other with an instability of 1.5x10(-17) at 1 s gate time.
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Affiliation(s)
- R Gebs
- Center for Applied Photonics, University of Konstanz, 78457 Konstanz, Germany.
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23
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Shan X, Zhang X, Mazurenko DA, Blaaderen AV, Dijkhuis JI, Hudert F, Dekorsy T. Acoustic vibrations in nanosized gold-shell particles. ACTA ACUST UNITED AC 2007. [DOI: 10.1088/1742-6596/92/1/012035] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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24
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Hudert F, Bartels A, Janke C, Dekorsy T, Köhler K. Coherent acoustic phonons in phonon cavities investigated by asynchronous optical sampling. ACTA ACUST UNITED AC 2007. [DOI: 10.1088/1742-6596/92/1/012012] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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25
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Abstract
We tailor the shape and phase of the pump-pulse spectrum in order to study coherent lattice dynamics in tellurium. Employing coherent control by splitting the pump pulse into a two-pulse sequence, we show that the oscillations due to A(1) coherent phonons can be cancelled but not enhanced as compared to single-pulse excitation of the same energy. We further demonstrate that a crucial factor for coherent phonon generation seems to be the bandwidth of the pulse spectrum. We observe that the coherent amplitude for long pump pulses decreases exponentially with pulse duration for both Gaussian and rectangular pulses. Finally, by varying the pulse chirp, we show that the coherent amplitude is independent of the chirp sign while the oscillation lifetime is slightly dependent on the chirp sign.
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Affiliation(s)
- O V Misochko
- Institute of Solid State Physics, Russian Academy of Sciences, 142432 Chernogolovka, Moscow region, Russia
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26
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Bartels A, Cerna R, Kistner C, Thoma A, Hudert F, Janke C, Dekorsy T. Ultrafast time-domain spectroscopy based on high-speed asynchronous optical sampling. Rev Sci Instrum 2007; 78:035107. [PMID: 17411217 DOI: 10.1063/1.2714048] [Citation(s) in RCA: 145] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
High-speed asynchronous optical sampling (ASOPS) is a novel technique for ultrafast time-domain spectroscopy (TDS). It employs two mode-locked femtosecond oscillators operating at a fixed repetition frequency difference as sources of pump and probe pulses. We present a system where the 1 GHz pulse repetition frequencies of two Ti:sapphire oscillators are linked at an offset of Deltaf(R)=10 kHz. As a result, their relative time delay is repetitively ramped from zero to 1 ns within a scan time of 100 micros. Mechanical delay scanners common to conventional TDS systems are eliminated, thus systematic errors due to beam pointing instabilities and spot size variations are avoided when long time delays are scanned. Owing to the multikilohertz scan-rate, high-speed ASOPS permits data acquisition speeds impossible with conventional schemes. Within only 1 s of data acquisition time, a signal resolution of 6 x 10(-7) is achieved for optical pump-probe spectroscopy over a time-delay window of 1 ns. When applied to terahertz TDS, the same acquisition time yields high-resolution terahertz spectra with 37 dB signal-to-noise ratio under nitrogen purging of the spectrometer. Spectra with 57 dB are obtained within 2 min. A new approach to perform the offset lock between the two femtosecond oscillators in a master-slave configuration using a frequency shifter at the third harmonic of the pulse repetition frequency is employed. This approach permits an unprecedented time-delay resolution of better than 160 fs. High-speed ASOPS provides the functionality of an all-optical oscilloscope with a bandwidth in excess of 3000 GHz and with 1 GHz frequency resolution.
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Affiliation(s)
- A Bartels
- Department of Physics and Center for Applied Photonics, University of Konstanz, D-78457 Konstanz, Germany
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27
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Dekorsy T, Hudert F, Cerna R, Schäfer H, Janke C, Bartels A, Köhler K, Braun S, Wiemer M, Mantl S. Coherent acoustic phonons in nanostructures investigated by asynchronous optical sampling. ACTA ACUST UNITED AC 2006. [DOI: 10.1117/12.687052] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
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28
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Bartels A, Thoma A, Janke C, Dekorsy T, Dreyhaupt A, Winnerl S, Helm M. High-resolution THz spectrometer with kHz scan rates. Opt Express 2006; 14:430-437. [PMID: 19503357 DOI: 10.1364/opex.14.000430] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
We demonstrate a rapid scanning high-resolution THz spectrometer capable of acquiring THz field transients with 1 ns duration without mechanical delay line. The THz spectrometer is based on two 1-GHz Ti:sapphire femtosecond lasers which are linked with a fixed repetition rate difference in order to perform high-speed asynchronous optical sampling. One laser drives a high-efficiency large-area GaAs based THz emitter, the other laser is used for electro-optic detection of the emitted THz-field. At a scan rate of 9 kHz a time resolution of 230 fs is accomplished. High-resolution spectra from 50 GHz up to 3 THz are obtained and water absorption lines with a width of 11 GHz are observed. The use of femtosecond lasers with 1 GHz repetition rate is essential to obtain rapid scanning and high time-resolution at the same time.
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Dekorsy T, Yakovlev VA, Seidel W, Helm M, Keilmann F. Infrared-phonon-polariton resonance of the nonlinear susceptibility in GaAs. Phys Rev Lett 2003; 90:055508. [PMID: 12633374 DOI: 10.1103/physrevlett.90.055508] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/02/2002] [Indexed: 05/24/2023]
Abstract
Nonlinear probing of the fundamental lattice vibration of polar crystals is shown to reveal insight into higher-order cohesive lattice forces. With a free-electron laser tunable in the far infrared we experimentally investigate the dispersion of the second-order susceptibility due to the phonon resonance in GaAs. We observe a strong resonance enhancement of second harmonic light generation at half the optical phonon frequency, and in addition a minimum at a higher frequency below the phonon frequency. Measuring this frequency and comparison to a theoretical model allows the determination of competing higher-order lattice forces.
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Affiliation(s)
- T Dekorsy
- Institute of Ion Beam Physics and Materials Research, Forschungszentrum Rossendorf, P.O. Box 510119, 01314 Dresden, Germany
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Misochko OV, Georgiev N, Dekorsy T, Helm M. Two crossovers in the Pseudogap regime of YBa 2Cu 3O (7-delta) superconductors observed by ultrafast spectroscopy. Phys Rev Lett 2002; 89:067002. [PMID: 12190603 DOI: 10.1103/physrevlett.89.067002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/07/2001] [Indexed: 05/23/2023]
Abstract
We have investigated the temperature dependence of the optical reflectivity on a femtosecond scale in a near optimally doped YBa 2Cu 3O (7-delta) superconductor. The combined study of the lattice and carrier dynamics at temperatures above T(c) allows us to identify two crossover temperatures in the normal state, giving evidence for an inhomogeneity of the pseudogap regime. These crossovers exhibit a clear hysteresis behavior depending on the direction of temperature change. The carrier and lattice dynamics within the crossover regimes show distinct differences from and similarities to the superconducting state, which may help in choosing between the competing theories for the pseudogap state.
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Affiliation(s)
- O V Misochko
- Institute for Ion Beam Physics and Materials Research, Research Center Rossendorf, P.O. Box 510119, D-01314 Dresden, Germany
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31
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Yee KJ, Lim YS, Dekorsy T, Kim DS. Mechanisms for the generation of coherent longitudinal-optical phonons in GaAs /AlGaAs multiple quantum wells. Phys Rev Lett 2001; 86:1630-1633. [PMID: 11290210 DOI: 10.1103/physrevlett.86.1630] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/29/2000] [Indexed: 05/23/2023]
Abstract
We show that coherent optical phonons in GaAs multiple quantum wells are generated in a completely different way as compared to bulk GaAs. Unlike in bulk GaAs where the ultrafast screening of electric fields by photogenerated charge carriers is known to be dominant, three distinctive generation mechanisms contribute simultaneously in multiple quantum wells. The interplay between impulsive Raman scattering, forbidden Raman scattering, and screening of surface electric fields, whose relative strengths are determined by laser intensity, detuning from the exciton resonance, and the barrier width, generates a rich variety of new phenomena.
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Affiliation(s)
- K J Yee
- Department of Physics, Seoul National University, Korea
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32
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Dekorsy T, Bartels A, Kurz H, Kohler K, Hey R, Ploog K. Coupled bloch-phonon oscillations in semiconductor superlattices. Phys Rev Lett 2000; 85:1080-1083. [PMID: 10991479 DOI: 10.1103/physrevlett.85.1080] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/1999] [Indexed: 05/23/2023]
Abstract
We investigate coherent Bloch oscillations in GaAs/AlxGa1-xAs superlattices with electronic miniband widths larger than the optical phonon energy. In these superlattices the Bloch frequency can be tuned into resonance with the optical phonon. Close to resonance a direct coupling of Bloch oscillations to LO phonons is observed which gives rise to the coherent excitation of LO phonons. The density necessary for driving coherent LO phonons via Bloch oscillations is about 2 orders of magnitude smaller than the density necessary to drive coherent LO phonons in bulk GaAs. The experimental observations are confirmed by the theoretical description of this phenomenon [A.W. Ghosh et al., Phys. Rev. Lett. 85, 1084 (2000)].
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Affiliation(s)
- T Dekorsy
- Institut fur Halbleitertechnik, RWTH Aachen, D-52056 Aachen, Germany
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33
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Bartels A, Dekorsy T, Kurz H. Impulsive excitation of phonon-pair combination states by second-order raman scattering. Phys Rev Lett 2000; 84:2981-2984. [PMID: 11018991 DOI: 10.1103/physrevlett.84.2981] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/1999] [Indexed: 05/23/2023]
Abstract
The excitation of (100)-oriented KTaO3 with 25-fs laser pulses impulsively drives phonon-pair combination states via second-order Raman scattering. Oscillations in the phonon-amplitude covariance at the sum and difference frequency of the two involved phonons are observed in a spectrally and temporally resolved pump-probe experiment. Transmission changes of the sample are dominated by contributions of wave vector conserving phonon-pair combinations from the entire Brillouin zone that have maxima in their combined density of states. For low temperatures the temperature dependence of the covariance oscillations of different phonon combinations is reproduced by a quantum-mechanical model.
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Affiliation(s)
- A Bartels
- Institut fur Halbleitertechnik, Rheinisch-Westfalische Technische Hochschule Aachen, Sommerfeldstrasse 24, D-52056 Aachen, Germany
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Abstract
A formation process for semiconductor quantum dots based on a surface instability induced by ion sputtering under normal incidence is presented. Crystalline dots 35 nanometers in diameter and arranged in a regular hexagonal lattice were produced on gallium antimonide surfaces. The formation mechanism relies on a natural self-organization mechanism that occurs during the erosion of surfaces, which is based on the interplay between roughening induced by ion sputtering and smoothing due to surface diffusion.
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Affiliation(s)
- S Facsko
- Institute of Semiconductor Electronics, Rheinisch-Westfälische Technische Hochschule Aachen, Sommerfeldstrasse 24, 52074 Aachen, Germany. Institut für Hochfrequenztechnik, TU Darmstadt, Merckstrasse 25, 64283 Darmstadt, Germany
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Bartels A, Dekorsy T, Kurz H. Femtosecond Ti:sapphire ring laser with a 2-GHz repetition rate and its application in time-resolved spectroscopy. Opt Lett 1999; 24:996-998. [PMID: 18073921 DOI: 10.1364/ol.24.000996] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
A Kerr-lens mode-locked femtosecond Ti:sapphire laser operating at a repetition rate of 2 GHz is demonstrated. A mirror-dispersion-controlled unidirectional ring cavity delivers nearly bandwidth-limited pulses of 23-fs length. Mode locking is self-starting without a hard aperture in the cavity. The advantages of this high-repetition-rate oscillator in optical time-resolved spectroscopy are demonstrated.
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Dekorsy T, Kim AM, Cho GC, Hunsche S, Bakker HJ, Kurz H, Chuang SL, Köhler K. Quantum Coherence of Continuum States in the Valence Band of GaAs Quantum Wells. Phys Rev Lett 1996; 77:3045-3048. [PMID: 10062117 DOI: 10.1103/physrevlett.77.3045] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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38
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Cho GC, Dekorsy T, Bakker HJ, Kurz H, Kohl A, Opitz B. Bloch oscillations in In-Ga-As-P/In-Ga-As-P heterostructures observed with time-resolved transmission spectroscopy. Phys Rev B Condens Matter 1996; 54:4420-4423. [PMID: 9986386 DOI: 10.1103/physrevb.54.4420] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Cho GC, Bakker HJ, Dekorsy T, Kurz H. Time-resolved observation of coherent phonons by the Franz-Keldysh effect. Phys Rev B Condens Matter 1996; 53:6904-6907. [PMID: 9982118 DOI: 10.1103/physrevb.53.6904] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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40
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Dekorsy T, Auer H, Bakker HJ, Roskos HG, Kurz H. THz electromagnetic emission by coherent infrared-active phonons. Phys Rev B Condens Matter 1996; 53:4005-4014. [PMID: 9983955 DOI: 10.1103/physrevb.53.4005] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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41
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Dekorsy T, Kim AM, Cho GC, Kurz H, Kuznetsov AV, Förster A. Subpicosecond coherent carrier-phonon dynamics in semiconductor heterostructures. Phys Rev B Condens Matter 1996; 53:1531-1538. [PMID: 9983616 DOI: 10.1103/physrevb.53.1531] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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42
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Leisching P, Ott R, Bolivar PH, Dekorsy T, Bakker HJ, Roskos HG, Kurz H, Köhler K. External-field-induced electric dipole moment of biexcitons in a semiconductor. Phys Rev B Condens Matter 1995; 52:16993-16996. [PMID: 9981113 DOI: 10.1103/physrevb.52.r16993] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Leisching P, Dekorsy T, Bakker HJ, Kurz H, Köhler K. Exceptionally slow dephasing of electronic continuum states in a semiconductor. Phys Rev B Condens Matter 1995; 51:18015-18018. [PMID: 9978844 DOI: 10.1103/physrevb.51.18015] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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46
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Dekorsy T, Auer H, Waschke C, Bakker HJ, Roskos HG, Kurz AH, Wagner V, Grosse P. Emission of Submillimeter Electromagnetic Waves by Coherent Phonons. Phys Rev Lett 1995; 74:738-741. [PMID: 10058835 DOI: 10.1103/physrevlett.74.738] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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47
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Heesel H, Hunsche S, Mikkelsen H, Dekorsy T, Leo K, Kurz H. Dynamics of electric field screening in a bulk GaAs modulator. Phys Rev B Condens Matter 1993; 47:16000-16003. [PMID: 10006011 DOI: 10.1103/physrevb.47.16000] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Dekorsy T, Pfeifer T, Kütt W, Kurz H. Subpicosecond carrier transport in GaAs surface-space-charge fields. Phys Rev B Condens Matter 1993; 47:3842-3849. [PMID: 10006492 DOI: 10.1103/physrevb.47.3842] [Citation(s) in RCA: 68] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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50
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Pfeifer T, Dekorsy T, K�tt W, Kurz H. Generation mechanism for coherent LO phonons in surface-space-charge fields of III-V-compounds. ACTA ACUST UNITED AC 1992. [DOI: 10.1007/bf00348337] [Citation(s) in RCA: 79] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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