151
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Petersen J, Mitrić R, Bonacić-Koutecký V, Wolf JP, Roslund J, Rabitz H. How shaped light discriminates nearly identical biochromophores. PHYSICAL REVIEW LETTERS 2010; 105:073003. [PMID: 20868039 DOI: 10.1103/physrevlett.105.073003] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/11/2010] [Indexed: 05/29/2023]
Abstract
We present a general mechanism for successful discrimination of spectroscopically indistinguishable biochromophores by shaped light. For this purpose we use nonadiabatic dynamics in excited electronic states in the frame of the field-induced surface hopping method driven by the experimentally shaped laser fields. Our findings show that optimal laser fields drive low-frequency vibrational modes localized in the side chains of two biochromophores, thus selecting the parts of their potential energy surfaces characterized by different transition dipole moments leading to different ionization probabilities. The presented mechanism leads to selective fluorescence depletion which serves as a discrimination signal. Our findings offer a promising perspective for using optimally shaped laser pulses in bioanalytical applications by increasing the selectivity beyond the current capability.
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Affiliation(s)
- Jens Petersen
- Department of Chemistry, Humboldt-Universität zu Berlin, Brook-Taylor-Str. 2, 12489 Berlin, Germany
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152
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Anderson A, Deryckx KS, Xu XG, Steinmeyer G, Raschke MB. Few-femtosecond plasmon dephasing of a single metallic nanostructure from optical response function reconstruction by interferometric frequency resolved optical gating. NANO LETTERS 2010; 10:2519-24. [PMID: 20518538 DOI: 10.1021/nl101090s] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
The precise characterization of the ultrafast optical response of metals and metallic nanostructures has remained an experimental challenge. We probe the few-femtosecond electronic dephasing of a local surface plasmon polariton excitation using symmetry-selective second-harmonic (SH) Rayleigh scattering of a nanoscopic conical gold tip as an individual plasmonic nanostructure. The full reconstruction of the optical response function of the plasmon excitation with phase and amplitude without any model assumptions is demonstrated from the analysis of the two-dimensional spectrogram obtained by simultaneous time- and frequency-domain SH measurements, using interferometric frequency resolved optical gating. The measured dephasing time of T(2) = 18 +/- 5 fs indicates the plasmon damping is dominated by nonradiative decay, consistent with a Drude-Sommerfeld dielectric response for gold. Even for the nominally homogeneous localized plasmon response, deviations are observed from the ideal harmonic oscillator phase behavior, which may reflect the underlying inhomogeneous electronic response with its different scattering channels. The presented technique is generally applicable for the reconstruction of the plasmon dynamics of complex nanostructures: information that cannot be obtained by conventional dark-field scattering.
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Affiliation(s)
- Alexandria Anderson
- Department of Chemistry, University of Washington, Seattle, Washington 98195, USA
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153
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Baida FI. Spatiotemporal sub-wavelength near-field light localization. OPTICS EXPRESS 2010; 18:14812-14819. [PMID: 20639968 DOI: 10.1364/oe.18.014812] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
The control and localization of light at sub-wavelength scale are theoretically demonstrated with a very simple sub-wavelength dimension structure. This is demonstrated through a peculiar structure that can support localized modes which are not linked to any plasmon resonance. It is based on the acronym "FEMTO" that is designed using 26 sub-wavelength rectangular apertures engraved into perfectly conducting metal screen. A polarization-sensitive guided mode through these nano-apertures is at the origin of the light localization. Consequently, sub-wavelength light spots can be achieved with very simple structures illuminated by temporally shaped plane waves. Three parameters are temporally controlled for this purpose: the polarization, the wavelength and the amplitude of the incident beam. It is also demonstrated that replacing the perfect conductor by a real metal with dispersion leads to accentuate both the light confinement and its localization. These results open the path to the conception of optical nano-structures dedicated to sub-wavelength light addressing.
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Affiliation(s)
- Fadi I Baida
- Département d'Optique P.M. Duffieux, Institut FEMTO-ST, CNRS UMR 6174, Université de Franche-Comté, 25030 Besançon Cedex, France.
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154
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Huang JS, Kern J, Geisler P, Weinmann P, Kamp M, Forchel A, Biagioni P, Hecht B. Mode imaging and selection in strongly coupled nanoantennas. NANO LETTERS 2010; 10:2105-2110. [PMID: 20411912 DOI: 10.1021/nl100614p] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
The number of eigenmodes in plasmonic nanostructures increases with complexity due to mode hybridization, raising the need for efficient mode characterization and selection. Here we experimentally demonstrate direct imaging and selective excitation of the "bonding" and "antibonding" plasmon mode in symmetric dipole nanoantennas using confocal two-photon photoluminescence mapping. Excitation of a high-quality-factor antibonding resonance manifests itself as a two-lobed pattern instead of the single spot observed for the broad "bonding" resonance in accordance with numerical simulations. The two-lobed pattern is observed due to the fact that excitation of the antibonding mode is forbidden for symmetric excitation at the feedgap, while concomitantly the mode energy splitting is large enough to suppress excitation of the "bonding" mode. The controlled excitation of modes in strongly coupled plasmonic nanostructures is mandatory for efficient sensors, in coherent control as well as for implementing well-defined functionalities in complex plasmonic devices.
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Affiliation(s)
- Jer-Shing Huang
- Nano-Optics and Biophotonics Group, Experimentelle Physik 5, Physikalisches Institut, Wilhelm-Conrad-Röntgen-Center for Complex Material Systems, Universität Würzburg, Am Hubland, D-97074 Würzburg, Germany.
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155
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Reiserer AA, Huang JS, Hecht B, Brixner T. Subwavelength broadband splitters and switches for femtosecond plasmonic signals. OPTICS EXPRESS 2010; 18:11810-11820. [PMID: 20589042 DOI: 10.1364/oe.18.011810] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Numerical simulations and an analytic approach based on transmission line theory are used to design splitters for nano-plasmonic signal processing that allow to arbitrarily adjust the ratio of transmission from an input into two different output arms. By adjusting the geometrical parameters of the structure, either a high bandwidth or a sharp transmission resonance is obtained. Switching between the two arms can be achieved by modulating the effective refractive index of the waveguide. Employing the instantaneous Kerr effect, switching rates in the THz regime are potentially feasible. The suggested devices are of interest for future applications in nanoplasmonic information processing.
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Affiliation(s)
- Andreas A Reiserer
- 1 Institut fr Physikalische und Theoretische Chemie, Universitt Wrzburg, Am Hubland, 97074, Wrzburg, Germany
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156
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Large N, Abb M, Aizpurua J, Muskens OL. Photoconductively loaded plasmonic nanoantenna as building block for ultracompact optical switches. NANO LETTERS 2010; 10:1741-1746. [PMID: 20405903 DOI: 10.1021/nl1001636] [Citation(s) in RCA: 78] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
We propose and explore theoretically a new concept of ultrafast optical switches based on nonlinear plasmonic nanoantennas. The antenna nanoswitch operates on the transition from the capacitive to conductive coupling regimes between two closely spaced metal nanorods. By filling the antenna gap with amorphous silicon, progressive antenna-gap loading is achieved due to variations in the free-carrier density in the semiconductor. Strong modification of the antenna response is observed both in the far-field response and in the local near-field intensity. The large modulation depth, low switching threshold, and potentially ultrafast time response of antenna switches holds promise for applications ranging from integrated nanophotonic circuits to quantum information devices.
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Affiliation(s)
- Nicolas Large
- Centro de Fisica de Materiales CSIC-UPV/EHU and Donostia International Physics Center, DIPC, Paseo Manuel Lardizabal 4, Donostia-San Sebastian, Spain
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157
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Abstract
Resonant nanoplasmonic structures have long been recognized for their unique applications in subwavelength control of light for enhanced transmission, focussing, field confinement, decay rate management, etc. Increasingly, they are also integrated in electro-optical analytical sensors, shrinking the active volume while at the same time improving sensitivity and specificity. The microscopic imaging of resonances in such structures and also their dynamic variations has seen dramatic advances in recent years. In this Minireview we outline the current status of this rapidly evolving field, discussing both optical and electron microscopy approaches, the limiting issues in spatial resolution and data interpretation, the quantities that can be recorded, as well as the growing importance of time-resolving methods.
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Affiliation(s)
- Ralf Vogelgesang
- Nanoscale Science Department, Max-Planck-Institute for Solid State Research, Heisenbergstrasse 1, D-70569, Stuttgart, Germany.
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158
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Utikal T, Stockman MI, Heberle AP, Lippitz M, Giessen H. All-optical control of the ultrafast dynamics of a hybrid plasmonic system. PHYSICAL REVIEW LETTERS 2010; 104:113903. [PMID: 20366478 DOI: 10.1103/physrevlett.104.113903] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/28/2009] [Revised: 02/17/2010] [Indexed: 05/06/2023]
Abstract
We demonstrate complete all-optical and phase-stable control of the linear optical polarization and the nonlinear coherent response (third-harmonic generation) of a hybrid nanoplasmonic-photonic system. A few tens of femtoseconds after the excitation, we turn the response on and off at any given point in time and probe its temporal evolution throughout the control process with a three-pulse nonlinear optical technique. After being switched off, the polarization and the nonlinear radiation remain off permanently. All experiments agree well with numerical simulations based on a damped harmonic oscillator model.
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Affiliation(s)
- Tobias Utikal
- 4th Physics Institute and Research Center SCoPE, University of Stuttgart, Pfaffenwaldring 57, 70550 Stuttgart, Germany
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159
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Abstract
The most general investigation and exploitation of light-induced processes require simultaneous control over spatial and temporal properties of the electromagnetic field on a femtosecond time and nanometer length scale. Based on the combination of polarization pulse shaping and time-resolved two-photon photoemission electron microscopy, we demonstrate such control over nanoscale spatial and ultrafast temporal degrees of freedom of an electromagnetic excitation in the vicinity of a nanostructure. The time-resolved cross-correlation measurement of the local photoemission yield reveals the switching of the nanolocalized optical near-field distribution with a lateral resolution well below the diffraction limit and a temporal resolution on the femtosecond time scale. In addition, successful adaptive spatiotemporal control demonstrates the flexibility of the method. This flexible simultaneous control of temporal and spatial properties of nanophotonic excitations opens new possibilities to tailor and optimize the light-matter interaction in spectroscopic methods as well as in nanophotonic applications.
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160
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Pazos-Pérez N, Barbosa S, Rodríguez-Lorenzo L, Aldeanueva-Potel P, Pérez-Juste J, Pastoriza-Santos I, Alvarez-Puebla RA, Liz-Marzán LM. Growth of Sharp Tips on Gold Nanowires Leads to Increased Surface-Enhanced Raman Scattering Activity. J Phys Chem Lett 2010; 1:24-27. [PMID: 26700846 DOI: 10.1021/jz100820m] [Citation(s) in RCA: 177] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
We report the formation of gold nanoparticles with a novel and useful morphology, comprising nanowires fully covered with sharp tips (thorned nanowires). The synthesis is based on a seeded-growth approach based the rapid overgrowth of ultrathin gold wires in N,N-dimethylformamide, in the presence of poly(vinylpyrrolidone). The process allows a fine control over the thickness of the final wires, as well as the tunability of the number and sharpness of the thorns. These new plasmonic nanostructures display extremely strong optical enhancing properties and can be readily used as platforms for SERS and for integration in ultrasensitive optical devices.
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Affiliation(s)
- Nicolás Pazos-Pérez
- Departamento de Química Física and Unidad Asociada CSIC, Universidade de Vigo, 36310 Vigo, Spain
| | - Silvia Barbosa
- Departamento de Química Física and Unidad Asociada CSIC, Universidade de Vigo, 36310 Vigo, Spain
| | - Laura Rodríguez-Lorenzo
- Departamento de Química Física and Unidad Asociada CSIC, Universidade de Vigo, 36310 Vigo, Spain
| | - Paula Aldeanueva-Potel
- Departamento de Química Física and Unidad Asociada CSIC, Universidade de Vigo, 36310 Vigo, Spain
| | - Jorge Pérez-Juste
- Departamento de Química Física and Unidad Asociada CSIC, Universidade de Vigo, 36310 Vigo, Spain
| | - Isabel Pastoriza-Santos
- Departamento de Química Física and Unidad Asociada CSIC, Universidade de Vigo, 36310 Vigo, Spain
| | - Ramón A Alvarez-Puebla
- Departamento de Química Física and Unidad Asociada CSIC, Universidade de Vigo, 36310 Vigo, Spain
| | - Luis M Liz-Marzán
- Departamento de Química Física and Unidad Asociada CSIC, Universidade de Vigo, 36310 Vigo, Spain
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161
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Renger J, Quidant R, van Hulst N, Palomba S, Novotny L. Free-space excitation of propagating surface plasmon polaritons by nonlinear four-wave mixing. PHYSICAL REVIEW LETTERS 2009; 103:266802. [PMID: 20366329 DOI: 10.1103/physrevlett.103.266802] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/25/2009] [Revised: 11/25/2009] [Indexed: 05/29/2023]
Abstract
A unique feature of surface plasmon polaritons (SPPs) is that their in-plane momentum is larger than the momentum of free-propagating photons of the same energy. Therefore, it is believed that they can be excited only by evanescent fields created by total internal reflection or by local scattering. Here, we provide the first demonstration of free-space excitation of surface plasmons by means of nonlinear four-wave mixing. The process involves the vectorial addition of the momenta of three incident photons, making it possible to penetrate the light cone and directly couple to the SPP dispersion curve. Using this technique, surface plasmons can be launched on any metal surface by simply overlapping two beams of laser pulses incident from resonant directions. The excitation scheme is also applicable to other bound modes, such as waveguide modes, surface phonon polaritons, and excitations of 2D electron gases.
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Affiliation(s)
- Jan Renger
- Institut de Ciencies Fotoniques, Mediterranean Technology Park, 08860 Castelldefels (Barcelona), Spain
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162
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Yanagisawa H, Hafner C, Doná P, Klöckner M, Leuenberger D, Greber T, Hengsberger M, Osterwalder J. Optical control of field-emission sites by femtosecond laser pulses. PHYSICAL REVIEW LETTERS 2009; 103:257603. [PMID: 20366286 DOI: 10.1103/physrevlett.103.257603] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/07/2009] [Indexed: 05/24/2023]
Abstract
We have investigated field-emission patterns from a clean tungsten tip apex induced by femtosecond laser pulses. Strongly asymmetric modulations of the field-emission intensity distributions are observed depending on the polarization of the light and the laser incidence direction relative to the azimuthal orientation of tip apex. In effect, we have realized an ultrafast pulsed field-emission source with site selectivity. Simulations of local fields on the tip apex and of electron emission patterns based on photoexcited nonequilibrium electron distributions explain our observations quantitatively.
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Affiliation(s)
- Hirofumi Yanagisawa
- Physik Institut, Universität Zürich, Winterthurerstrasse 190, CH-8057 Zürich, Switzerland.
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163
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Park S, Won Hahn J. Plasmonic data storage medium with metallic nano-aperture array embedded in dielectric material. OPTICS EXPRESS 2009; 17:20203-20210. [PMID: 19997244 DOI: 10.1364/oe.17.020203] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
We propose a plasmonic data storage medium with a high-transmission metal aperture array embedded in a dielectric material. Bowtie apertures, having an outline of 80 nm and a ridge gap of 30 nm, are arranged in a two dimensional array with a bit pitch of 100 nm and a track pitch of 280 nm. Using the finite differential time domain (FDTD) method, we calculate the exposure power needed to record optical data, the contrast for readability of recorded data, and cross talk between the main track and adjacent tracks. Compared to a conventional blu-ray disc, the exposure power needed to record optical data in the proposed plasmonic data storage medium is less than a quarter of the conventional threshold power, and the density of the data storage is about 1.8 times larger.
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Affiliation(s)
- Sinjeung Park
- School of Mechanical Engineering, Yonsei University, 262 Seongsanno, Seodaemun-gu, Seoul 120-749, Korea
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164
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Esumi Y, Kabir MD, Kannari F. Spatiotemporal vector pulse shaping of femtosecond laser pulses with a multi-pass two-dimensional spatial light modulator. OPTICS EXPRESS 2009; 17:19153-19159. [PMID: 20372651 DOI: 10.1364/oe.17.019153] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
A novel non-interferometric vector pulse-shaping scheme is developed for femtosecond laser pulses using a two-dimensional spatial light modulator (2D-SLM). By utilizing spatiotemporal pulse shaping obtainable by the 2D-SLM, we demonstrate spatiotemporal vector pulse shaping for the first time.
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Affiliation(s)
- Y Esumi
- Department of Electronics and Electrical Engineering, Keio University, Yokohama 223-8522, Japan
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165
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Reichelt M, Meier T. Shaping the spatiotemporal dynamics of the electron density in a hybrid metal-semiconductor nanostructure. OPTICS LETTERS 2009; 34:2900-2902. [PMID: 19794761 DOI: 10.1364/ol.34.002900] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
A one-dimensional semiconductor nanostructure is locally excited through a metal aperture. It is shown that the electron density can be coherently localized at desired spatial and temporal positions by using nontrivially shaped laser pulses. To obtain the optimized laser field, Bloch equations for a tight-binding model system are solved together with a genetic pulse-shaping algorithm. Full three-dimensional finite-difference time-domain (FDTD) simulations of the Maxwell-Bloch equations confirm the predicted coherent spatiotemporal control.
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Affiliation(s)
- Matthias Reichelt
- Department of Physics, University of Paderborn, Warburger Strasse 100, D-33098 Paderborn, Germany.
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166
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Volpe G, Cherukulappurath S, Juanola Parramon R, Molina-Terriza G, Quidant R. Controlling the optical near field of nanoantennas with spatial phase-shaped beams. NANO LETTERS 2009; 9:3608-3611. [PMID: 19639964 DOI: 10.1021/nl901821s] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
We report on a novel approach, based on sub-wavelength spatial phase variations at the focus of high-order beams, to reconfigure the optical near field distribution near plasmonic nanostructures. We first show how the introduction of phase jumps in the incident field driving a gap nanoantenna strongly affects its near field response. Beyond, we demonstrate the feasibility of exploiting this approach to selectively switch on and off hot-spots sites within a complex antenna architecture.
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Affiliation(s)
- Giorgio Volpe
- ICFO-Institut de Ciencies Fotoniques, Mediterranean Technology Park, 08860 Castelldefels, Barcelona, Spain
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167
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Stannigel K, König M, Niegemann J, Busch K. Discontinuous Galerkin time-domain computations of metallic nanostructures. OPTICS EXPRESS 2009; 17:14934-14947. [PMID: 19687972 DOI: 10.1364/oe.17.014934] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
We apply the three-dimensional Discontinuous-Galerkin Time-Domain method to the investigation of the optical properties of bar- and V-shaped metallic nanostructures on dielectric substrates. A flexible finite element-like mesh together with an expansion into high-order basis functions allows for an accurate resolution of complex geometries and strong field gradients. In turn, this provides accurate results on the optical response of realistic structures. We study in detail the influence of particle size and shape on resonance frequencies as well as on scattering and absorption efficiencies. Beyond a critical size which determines the onset of the quasi-static limit we find significant deviations from the quasi-static theory. Furthermore, we investigate the influence of the excitation by comparing normal illumination and attenuated total internal reflection setups. Finally, we examine the possibility of coherently controlling the local field enhancement of V-structures via chirped pulses.
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Affiliation(s)
- Kai Stannigel
- Institut für Theoretische Festkörperphysik, Universität Karlsruhe (TH), 76128 Karlsruhe, Germany.
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168
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Lin J, Weber N, Wirth A, Chew SH, Escher M, Merkel M, Kling MF, Stockman MI, Krausz F, Kleineberg U. Time of flight-photoemission electron microscope for ultrahigh spatiotemporal probing of nanoplasmonic optical fields. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2009; 21:314005. [PMID: 21828566 DOI: 10.1088/0953-8984/21/31/314005] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Nanoplasmonic excitations as generated by few-cycle laser pulses on metal nanostructures undergo ultrafast dynamics with timescales as short as a few hundred attoseconds (1 as = 10(-18) s). So far, the spatiotemporal dynamics of optical fields localized on the nanoscale (nanoplasmonic field) have been hidden from direct access in the real space and time domain. An approach which combines photoelectron emission microscopy and attosecond streaking spectroscopy and which provides direct and non-invasive access to the nanoplasmonic field with nanometer-scale spatial resolution and temporal resolution of the order of 100 as has been proposed (Stockman et al 2007 Nat. Photon. 1 539). To implement this approach, a time of flight-photoemission electron microscope (TOF-PEEM) with ∼25 nm spatial and ∼50 meV energy resolution, which has the potential to detect a nanoplasmonic field with nanometer spatial and attosecond temporal resolution, has been developed and characterized using a 400 nm/60 ps pulsed diode laser. The first experimental results obtained using this newly developed TOF-PEEM in a two-photon photoemission mode with a polycrystalline Cu sample and an Ag microstructure film show that the yield and the kinetic energy of the emitted photoelectrons are strongly affected by the nanolocalized plasmonic field.
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Affiliation(s)
- Jingquan Lin
- Changchun University of Science and Technology, Changchun 130022, People's Republic of China. Fakultät für Physik, Ludwig-Maximilians-Universität München, Am Coulombwall 1, 85748 Garching, Germany
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169
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Tuchscherer P, Rewitz C, Voronine DV, García de Abajo FJ, Pfeiffer W, Brixner T. Analytic coherent control of plasmon propagation in nanostructures. OPTICS EXPRESS 2009; 17:14235-59. [PMID: 19654834 DOI: 10.1364/oe.17.014235] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
We present general analytic solutions for optical coherent control of electromagnetic energy propagation in plasmonic nanostructures. Propagating modes are excited with tightly focused ultrashort laser pulses that are shaped in amplitude, phase, and polarization (ellipticity and orientation angle). We decouple the interplay between two main mechanisms which are essential for the control of local near-fields. First, the amplitudes and the phase difference of two laser pulse polarization components are used to guide linear flux to a desired spatial position. Second, temporal compression of the near-field at the target location is achieved using the remaining free laser pulse parameter to flatten the local spectral phase. The resulting enhancement of nonlinear signals from this intuitive analytic two-step process is compared to and confirmed by the results of an iterative adaptive learning loop in which an evolutionary algorithm performs a global optimization. Thus, we gain detailed insight into why a certain complex laser pulse shape leads to a particular control target. This analytic approach may also be useful in a number of other coherent control scenarios.
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Affiliation(s)
- Philip Tuchscherer
- Institut für Physikalische Chemie, Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
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170
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Dorfmüller J, Vogelgesang R, Weitz RT, Rockstuhl C, Etrich C, Pertsch T, Lederer F, Kern K. Fabry-Pérot resonances in one-dimensional plasmonic nanostructures. NANO LETTERS 2009; 9:2372-7. [PMID: 19472987 DOI: 10.1021/nl900900r] [Citation(s) in RCA: 139] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
We study the near-field optical behavior of Fabry-Pérot resonances in thin metal nanowires, also referred to as quasi one-dimensional plasmonic nanoantennas. From eigenmodes well beyond quadrupolar order we extract both, propagation constant and reflection phase of the guided surface plasmon polariton with superb accuracy. The combined symmetry breaking effects of oblique illumination and retardation allow the excitation of dipole forbidden, even order resonances. All measurements are supported by rigorous simulations of the experimental situation.
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Affiliation(s)
- Jens Dorfmüller
- Max-Planck-Institut fur Festkorperforschung, Heisenbergstr. 1, 70569 Stuttgart, Germany.
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171
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Abramavicius D, Palmieri B, Voronine DV, Šanda F, Mukamel S. Coherent multidimensional optical spectroscopy of excitons in molecular aggregates; quasiparticle versus supermolecule perspectives. Chem Rev 2009; 109:2350-408. [PMID: 19432416 PMCID: PMC2975548 DOI: 10.1021/cr800268n] [Citation(s) in RCA: 327] [Impact Index Per Article: 21.8] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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172
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Huang JS, Feichtner T, Biagioni P, Hecht B. Impedance matching and emission properties of nanoantennas in an optical nanocircuit. NANO LETTERS 2009; 9:1897-1902. [PMID: 19338279 DOI: 10.1021/nl803902t] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
An experimentally realizable prototype optical nanocircuit consisting of a receiving and an emitting nanoantenna connected by a two-wire optical transmission line is studied using finite-difference time- and frequency-domain simulations. To optimize the coupling between optical nanocircuit elements we apply impedance matching concepts in analogy to radio frequency technology. We show that the degree of impedance matching, and in particular the impedance of the emitting nanoantenna, can be inferred from the experimentally accessible standing wave pattern on the transmission line. We demonstrate the possibility of matching the nanoantenna impedance to the transmission line by variations of the antenna length and width realizable by modern microfabrication techniques. The radiation efficiency of the emitting antenna also depends on its geometry but is independent of the degree of impedance matching. The case study presented here provides the basis for experimental realizations of general optical nanocircuits based on readily available gold nanostructures and a large variety of derived novel devices.
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Affiliation(s)
- Jer-Shing Huang
- Nano-Optics & Biophotonics Group, Department of Experimental Physics 5, Rontgen Research Center for Complex Material Research, Physics Institute, University of Würzburg, Am Hubland, D-97074 Würzburg, Germany
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173
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Affiliation(s)
- Yaron Silberberg
- Department of Physics of Complex Systems, Weizmann Institute of Science, Rehovot 76100, Israel;
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174
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Weise F, Lindinger A. Full control over the electric field using four liquid crystal arrays. OPTICS LETTERS 2009; 34:1258-60. [PMID: 19370136 DOI: 10.1364/ol.34.001258] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
We present a femtosecond pulse shaper setup that is capable of shaping the phase, amplitude, and polarization simultaneously and independently. The modulator utilizes four liquid crystal arrays, a pair of half-wave plates, and a polarizer to gain full control of the electrical field. This is done in a common-path common-optic scheme without using interferometry. The functionality of the setup is demonstrated by using systematic parameter scans and example pulses.
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Affiliation(s)
- Fabian Weise
- Institut für Experimentalphysik, Freie Universität Berlin, Arnimallee 14, D-14195 Berlin, Germany.
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175
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Hommelhoff P, Kealhofer C, Aghajani-Talesh A, Sortais YR, Foreman SM, Kasevich MA. Extreme localization of electrons in space and time. Ultramicroscopy 2009; 109:423-9. [DOI: 10.1016/j.ultramic.2008.10.021] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2008] [Revised: 10/18/2008] [Accepted: 10/21/2008] [Indexed: 10/21/2022]
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176
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Berndt M, Rohmer M, Ashall B, Schneider C, Aeschlimann M, Zerulla D. Polarization selective near-field focusing on mesoscopic surface patterns with threefold symmetry measured with PEEM. OPTICS LETTERS 2009; 34:959-61. [PMID: 19340184 DOI: 10.1364/ol.34.000959] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Optically active surfaces that can provide strong localization of electromagnetic fields at predefined points are desired for applications that require high spatial resolution and high sensitivity. Here, we examine the geometric influences on, and polarization dependencies of, electromagnetic near fields on the surface of an array of tailor designed, mesoscalic, silver-coated structures with threefold symmetry characteristics. For spatially resolved mapping of the electromagnetic near fields and examining the influence of polarization, we use a photoelectron emission microscope. We find that the investigated structures not only provide an increase of the near-field intensity at their boundaries, but also that the symmetry centers of the structures focus energy in a polarization dependent manner. Changing the polarization of the incident light enables the localization of near-field intensities without displacing the excitation. Hence we show that breaking of symmetry can provide controllable centers of "hot spots" for the basis of an improved design to gain more efficient surface structures.
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Affiliation(s)
- Michael Berndt
- Max-Planck-Institute of Molecular Cell Biology and Genetics, Dresden, Germany
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177
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Wnuk P, Xuan LL, Slablab A, Tard C, Perruchas S, Gacoin T, Roch JF, Chauvat D, Radzewicz C. Coherent nonlinear emission from a single KTP nanoparticle with broadband femtosecond pulses. OPTICS EXPRESS 2009; 17:4652-4658. [PMID: 19293894 DOI: 10.1364/oe.17.004652] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
We demonstrate that the intensity of the second harmonic (SH) generated in KTiOPO(4) nanoparticles excited with femtosecond laser pulses increases with decreasing duration of the infrared pump pulses. The SH intensity scales, approximately, as the inverse of the laser pulse duration ranging between 13 fs and 200 fs. The SH intensity enhancement requires careful compensation of the high-order spectral phase, being achieved with a genetic algorithm. Using ultrashort laser pulses improves the signal-to-noise ratio and will allow the detection of 10-nm size particles. Finally, we demonstrate that the spectrum of broadband (100 nm) pulses can be shaped to generate non-degenerate sum-frequency mixing. This opens up access to the polarization degrees of freedom of this second-order nonlinear process at the nanoscale.
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Affiliation(s)
- Pawel Wnuk
- Institute of Experimental Physics, Warsaw University, Hoza 69, 00-681 Warsaw, Poland.
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178
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Chaudhuri D, Galusha JW, Walter MJ, Borys NJ, Bartl MH, Lupton JM. Toward subdiffraction transmission microscopy of diffuse materials with silver nanoparticle white-light beacons. NANO LETTERS 2009; 9:952-956. [PMID: 19193157 DOI: 10.1021/nl802819n] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
We demonstrate high resolution transmission microscopy in a conventional two-photon wide-field fluorescence microscope by exploiting nonlinear white light generation from clusters of silver nanoparticles placed beneath the specimen. Surface-enhanced two-photon luminescence occurs at nanoparticle hot spots in the form of spectrally broad, spatially confined light which can be exploited to determine the transmission properties of a sample placed on the silver nanoparticles. We demonstrate the versatility of the technique by revealing individual crystalline domains formed in the diffuse biological photonic crystals of the scales of a beetle. We can identify submicron changes between photonic crystal facets as well as the occurrence of stacked domains invisible to surface-sensitive methods. Control over wavelength, polarization, and pulse shape promises selective addressing of hot spots in nanoparticle assemblies for motionless spatial scanning of the transmission properties with subdiffraction resolution.
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Affiliation(s)
- Debansu Chaudhuri
- Department of Physics and Department of Chemistry, University of Utah, Salt Lake City, Utah 84112, USA
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179
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Golan B, Fradkin Z, Kopnov G, Oron D, Naaman R. Controlling two-photon photoemission using polarization pulse shaping. J Chem Phys 2009; 130:064705. [DOI: 10.1063/1.3077123] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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180
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Local Control Theory: Recent Applications to Energy and Particle Transfer Processes in Molecules. ADVANCES IN CHEMICAL PHYSICS 2009. [DOI: 10.1002/9780470431917.ch2] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/04/2023]
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181
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Surface Plasmon-Enhanced Photoemission and Electron Acceleration with Ultrashort Laser Pulses. ADVANCES IN IMAGING AND ELECTRON PHYSICS 2009. [DOI: 10.1016/s1076-5670(09)00006-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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182
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183
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184
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185
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186
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Gollub C, Kowalewski M, de Vivie-Riedle R. Monotonic convergent optimal control theory with strict limitations on the spectrum of optimized laser fields. PHYSICAL REVIEW LETTERS 2008; 101:073002. [PMID: 18764528 DOI: 10.1103/physrevlett.101.073002] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/24/2008] [Indexed: 05/26/2023]
Abstract
We present a modified optimal control scheme based on the Krotov method, which allows for strict limitations on the spectrum of the optimized laser fields. A frequency constraint is introduced and derived mathematically correct, without losing monotonic convergence of the algorithm. The method guarantees a close link to learning loop control experiments and is demonstrated for the challenging control of nonresonant Raman transitions, which are used to implement a set of global quantum gates for molecular vibrational qubits.
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Affiliation(s)
- Caroline Gollub
- Department of Chemistry, Ludwig-Maximilians-Universitat Miinchen, D-81377 Miinchen, Germany
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187
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Choi S, Park D, Lienau C, Jeong MS, Byeon CC, Ko DK, Kim DS. Femtosecond phase control of spatial localization of the optical near-field in a metal nanoslit array. OPTICS EXPRESS 2008; 16:12075-12083. [PMID: 18679481 DOI: 10.1364/oe.16.012075] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
We demonstrate spatial control of optical near-fields by femtosecond phase shaping in one-dimensional plasmonic structures. The near-field images display striking temporal-phase dependence, switching between double- and single-peak images within one lattice constant. The change of the near-field distribution is studied in the time and spectral domain. The spectral composition change observed by varying the time delay between two phase-locked femtosecond pulses explains the spatial control of the near-field images. Modal expansion calculations of linear light transmission using the surface impedance boundary condition are in excellent agreement with experiments.
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Affiliation(s)
- Soobong Choi
- Department of Physics and Astronomy, Seoul National University, Seoul 151-742, Korea
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188
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McLeod E, Arnold CB. Subwavelength direct-write nanopatterning using optically trapped microspheres. NATURE NANOTECHNOLOGY 2008; 3:413-7. [PMID: 18654565 DOI: 10.1038/nnano.2008.150] [Citation(s) in RCA: 126] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2008] [Accepted: 05/01/2008] [Indexed: 05/03/2023]
Abstract
A number of non-lithographic techniques are now available for processing materials on the nanoscale, including optical techniques capable of producing features that are much smaller than the wavelength of light used. However, these techniques can be limited in speed, ease of use, cost of implementation, or the range of patterns they can write. Here we report how Bessel beam laser trapping of microspheres near surfaces can be used to enable near-field direct-write subwavelength nanopatterning. Using the microsphere as an objective lens to focus the processing laser, we demonstrate arbitrary patterns and individual features with minimum sizes of approximately 100 nm (which is less than one-third the processing wavelength) and a positioning accuracy better than 40 nm in aqueous and chemical environments. Submicron spacing is maintained between the near-field objective and the substrate without active feedback control. If implemented with an array of optical traps, this approach could lead to a high-throughput probe-based method for patterning surfaces with subwavelength features.
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189
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Franco I, Shapiro M, Brumer P. Laser-induced currents along molecular wire junctions. J Chem Phys 2008; 128:244906. [PMID: 18601382 DOI: 10.1063/1.2940796] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
The treatment of the previous paper is extended to molecular wires. Specifically, the effect of electron-vibrational interactions on the electronic transport induced by femtosecond omega+2omega laser fields along unbiased molecular nanojunctions is investigated. For this, the photoinduced vibronic dynamics of trans-polyacetylene oligomers coupled to macroscopic metallic leads is followed in a mean-field mixed quantum-classical approximation. A reduced description of the dynamics is obtained by introducing projective lead-molecule couplings and deriving an effective Schrodinger equation satisfied by the orbitals in the molecular region. Two possible rectification mechanisms are identified and investigated. The first one relies on near-resonance photon-absorption and is shown to be fragile to the ultrafast electronic decoherence processes introduced by the wire's vibrations. The second one employs the dynamic Stark effect and is demonstrated to be highly efficient and robust to electron-vibrational interactions.
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Affiliation(s)
- Ignacio Franco
- Chemical Physics Theory Group, Department of Chemistry and Center for Quantum Information and Quantum Control, University of Toronto, Toronto, Ontario M5S 3H6, Canada
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190
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Winkelmann A, Lin WC, Bisio F, Petek H, Kirschner J. Interferometric control of spin-polarized electron populations at a metal surface observed by multiphoton photoemission. PHYSICAL REVIEW LETTERS 2008; 100:206601. [PMID: 18518563 DOI: 10.1103/physrevlett.100.206601] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2008] [Indexed: 05/26/2023]
Abstract
In an interferometric pump-probe experiment, we demonstrate the phase tuning of the spin polarization of photoelectrons emitted in a three-photon process from Cu(001). A phase shift of pi between delayed ultrafast circularly polarized light pulses can switch the spin polarization from +/-20% to -/+40%. In the delay regime of overlapping pulses, we show the dominating role of optical interference effects in determining the spin polarization. For longer delays, we detect the influence of the coherent material response, manifested in both the final state electron population as well as the final state spin polarization.
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Affiliation(s)
- Aimo Winkelmann
- Max-Planck Institut für Mikrostrukturphysik, Weinberg 2, D-06120 Halle (Saale), Germany.
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191
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Lévêque G, Martin OJF. Narrow-band multiresonant plasmon nanostructure for the coherent control of light: an optical analog of the xylophone. PHYSICAL REVIEW LETTERS 2008; 100:117402. [PMID: 18517826 DOI: 10.1103/physrevlett.100.117402] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/12/2007] [Indexed: 05/26/2023]
Abstract
We demonstrate that it is possible to combine several small metallic particles in a very compact geometry without loss of their individual modal properties by adding a gold metallic film underneath. This film essentially acts as a "ground plane" which channels the optical field of each particle and decreases the interparticle coupling. The localization of the electric field can then be controlled temporally by illuminating the chain with a chirped pulse. The sign of the chirp controls the excitation sequence of the particles with great flexibility.
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Affiliation(s)
- Gaëtan Lévêque
- Nanophotonics and Metrology Laboratory, Swiss Federal Institute of Technology Lausanne, EPFL-STI-NAM ELG Station 11, CH-1015 Lausanne, Switzerland.
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192
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Dombi P, Rácz P. Ultrafast monoenergetic electron source by optical waveform control of surface plasmons. OPTICS EXPRESS 2008; 16:2887-2893. [PMID: 18542373 DOI: 10.1364/oe.16.002887] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
We propose coherent control of photoelectron acceleration at metal surfaces mediated by surface plasmon polaritons. A high degree of spectral and spatial control of the emission process can be exercised by amplitude and phase controlling the optical waveform (including the carrier-envelope phase) of the plasmon generating few-cycle laser pulse. Numerical results show that the emitted electron beam is highly directional and monoenergetic suggesting applications in contemporary ultrafast methods where ultrashort, well-behaved electron pulses are required.
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Affiliation(s)
- Péter Dombi
- Research Institute for Solid-State Physics and Optics, H-1121 Budapest, Konkoly-Thege M. út 29-33, Hungary.
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193
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Stähler J, Bovensiepen U, Meyer M, Wolf M. A surface science approach to ultrafast electron transfer and solvation dynamics at interfaces. Chem Soc Rev 2008; 37:2180-90. [DOI: 10.1039/b800257f] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
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194
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Durach M, Rusina A, Stockman MI, Nelson K. Toward full spatiotemporal control on the nanoscale. NANO LETTERS 2007; 7:3145-9. [PMID: 17727301 DOI: 10.1021/nl071718g] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
We introduce an approach to implement full coherent control on nanometer length scales. It is based on spatiotemporal modulation of the surface plasmon polariton (SPP) fields at the thick edge of a nanowedge. The SPP wavepackets propagating toward the sharp edge of this nanowedge are compressed and adiabatically concentrated at a nanofocus, forming an ultrashort pulse of local fields. The profile of the focused waveform as a function of time and one spatial dimension is completely coherently controlled.
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Affiliation(s)
- Maxim Durach
- Department of Physics and Astronomy, Georgia State University, Atlanta, Georgia 30303, USA
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195
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Ropers C, Neacsu CC, Elsaesser T, Albrecht M, Raschke MB, Lienau C. Grating-coupling of surface plasmons onto metallic tips: a nanoconfined light source. NANO LETTERS 2007; 7:2784-8. [PMID: 17685661 DOI: 10.1021/nl071340m] [Citation(s) in RCA: 176] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
We describe and demonstrate a new nanometer-scale broadband light source. It is based on the grating-coupled excitation of surface plasmon polaritons (SPPs) on the shaft of a sharp conical metal taper with a tip radius of few tens of nanometers. Far-field excitation of linear nanoslit gratings results in the resonant generation of SPPs traveling over more than 10 mum to the tip apex and converging to an intense radiative local light spot. Such nanofabricated tips are expected to find various applications in nanospectroscopy, overcoming problems with background illumination in apertureless microscopy.
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Affiliation(s)
- C Ropers
- Max-Born-Institut für Nichtlineare Optik und Kurzzeitspektroskopie, D-12489 Berlin, Germany.
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196
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Konieczny M, Likos CN. From sea-urchins to starfishes: controlling the adsorption of star-branched polyelectrolytes on charged walls. SOFT MATTER 2007; 3:1130-1134. [PMID: 32900033 DOI: 10.1039/b708788h] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
We demonstrate that star-branched polyelectrolytes are a versatile soft component forming a variety of well-characterised conformations upon electrostatic complexation on oppositely charged planar surfaces. We discover and characterise five complexation shapes, described by a two-dimensional morphological order parameter. These shapes are distinguished on the basis of their deviations from sphericity, the orientation of the polyelectrolyte arms, and the equilibrium centre-to-surface distance of the stars. Conformational transformations can be steered by changing the electrostatic surface-star coupling and/or the star functionality. For low functionalities and/or strong external fields, full collapse of the star onto the wall, forming a starfish configuration, is observed. Otherwise, partially adsorbed states with a fraction of chains pointing away from the surface and with the star core being detached from the wall are formed.
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Affiliation(s)
- Martin Konieczny
- Institut für Theoretische Physik II: Weiche Materie, Heinrich-Heine-Universität Düsseldorf, Universitätsstraße 1, D-40225, Düsseldorf, Germany.
| | - Christos N Likos
- Institut für Theoretische Physik II: Weiche Materie, Heinrich-Heine-Universität Düsseldorf, Universitätsstraße 1, D-40225, Düsseldorf, Germany.
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197
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198
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Nuernberger P, Vogt G, Brixner T, Gerber G. Femtosecond quantum control of molecular dynamics in the condensed phase. Phys Chem Chem Phys 2007; 9:2470-97. [PMID: 17508081 DOI: 10.1039/b618760a] [Citation(s) in RCA: 130] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We review the progress in controlling quantum dynamical processes in the condensed phase with femtosecond laser pulses. Due to its high particle density the condensed phase has both high relevance and appeal for chemical synthesis. Thus, in recent years different methods have been developed to manipulate the dynamics of condensed-phase systems by changing one or multiple laser pulse parameters. Single-parameter control is often achieved by variation of the excitation pulse's wavelength, its linear chirp or its temporal subpulse separation in case of pulse sequences. Multiparameter control schemes are more flexible and provide a much larger parameter space for an optimal solution. This is realized in adaptive femtosecond quantum control, in which the optimal solution is iteratively obtained through the combination of an experimental feedback signal and an automated learning algorithm. Several experiments are presented that illustrate the different control concepts and highlight their broad applicability. These fascinating achievements show the continuous progress on the way towards the control of complex quantum reactions in the condensed phase.
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Affiliation(s)
- Patrick Nuernberger
- Universität Würzburg, Physikalisches Institut, Am Hubland, 97074 Würzburg, Germany
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