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P.J.S. van Capel

Bio: P.J.S. van Capel is an academic researcher from Utrecht University. The author has contributed to research in topics: Ultrashort pulse & Quantum well. The author has an hindex of 5, co-authored 14 publications receiving 171 citations.

Papers
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Journal ArticleDOI
TL;DR: Acoustic solitons formed during the propagation of a picosecond strain pulse in a GaAs crystal with a ZnSe/ZnMgSSe quantum well on top lead to exciton resonance energy shifts of up to 10 meV, and ultrafast frequency modulation, i.e., chirping, of the exciton transition.
Abstract: Acoustic solitons formed during the propagation of a picosecond strain pulse in a GaAs crystal with a ZnSe/ZnMgSSe quantum well on top lead to exciton resonance energy shifts of up to 10 meV, and ultrafast frequency modulation, i.e., chirping, of the exciton transition. The effects are well described by a theoretical analysis based on the Korteweg-de Vries equation and accounting for the properties of the excitons in the quantum well.

45 citations

Journal ArticleDOI
TL;DR: This work presents an overview of nonlinear ultrasonics since its first experimental demonstration at the beginning of this century to the more recent developments and shows various results obtained by different groups around the world with an emphasis on recent work.

36 citations

Journal ArticleDOI
TL;DR: In this paper, one-dimensional nonlinear propagation of high-amplitude acoustic waves in sapphire, for various sample temperatures, sample thicknesses, and pump capabilities, is studied.
Abstract: Received 12 November 2009; revised manuscript received 23 March 2010; published 13 April 2010We study one-dimensional nonlinear propagation of high-amplitude acoustic waves in sapphire, for varioussample temperatures, sample thicknesses, and pump fluences. Strain waves are generated in a 100-nm-thickchromium film and launched into the sapphire. For temperatures 60 K, damping can be neglected andpropagation is dominated by the nonlinear and dispersive properties of the sapphire substrate. An interfero-metric technique is used to detect the wave on an epitaxially grown 20-nm-thick Cr film at the opposite sideof the sample. At the lowest temperature of 18 K, a train of up to seven solitons is detected in sapphire for apump fluence of 11 mJ/cm

33 citations

Journal ArticleDOI
TL;DR: In this paper, the authors investigate acoustic and electromagnetic emission from optically excited strained piezoelectric In0.2Ga0.8N/GaN multiple quantum wells (MQWs), using optical pump-probe spectroscopy, time-resolved Brillouin scattering, and THz emission spectrum analysis.
Abstract: We investigate acoustic and electromagnetic emission from optically excited strained piezoelectric In0.2Ga0.8N/GaN multiple quantum wells (MQWs), using optical pump-probe spectroscopy, time-resolved Brillouin scattering, and THz emission spectroscopy. A direct comparison of detected acoustic signals and THz electromagnetic radiation signals demonstrates that transient strain generation in InGaN/GaN MQWs is correlated with electromagnetic THz generation, and both types of emission find their origin in ultrafast dynamical screening of the built-in piezoelectric field in the MQWs. The measured spectral intensity of the detected Brillouin signal corresponds to a maximum strain amplitude of generated acoustic pulses of 2%. This value coincides with the static lattice-mismatch-induced strain in In0.2Ga0.8N/GaN, demonstrating the total release of static strain in MQWs via impulsive THz acoustic emission. This confirms the ultrafast dynamical screening mechanism in MQWs as a highly efficient method for impulsive strain generation

28 citations

Journal ArticleDOI
TL;DR: In this article, the authors used pump-probe spectroscopy to study the propagation of laser-excited longitudinal, high-amplitude, coherent picosecond acoustic phonon wave packets in thin sapphire slabs at room temperature.
Abstract: Using pump-probe spectroscopy, we study the propagation of laser-excited longitudinal, high-amplitude, coherent picosecond acoustic phonon wave packets in thin sapphire slabs at room temperature. We observe significant stretching of the wave packet up to several tens of picoseconds, accompanied by strong steepening of the wave fronts. The results demonstrate the supersonic and subsonic nature of propagation in viscous nonlinear media and more specifically the presence of acoustic frequencies in the wave packet as high as 500GHz. All experimental data are in excellent agreement with simulations based on Burgers’ equation.

23 citations


Cited by
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Journal ArticleDOI
TL;DR: In this paper, the authors discuss how the use of hybrid multilayer structures combining different functionalities allows the development of active plasmonic devices and new metrologies.
Abstract: Surface plasmon–polaritons are electromagnetic waves that propagate along metal–dielectric interfaces and exist over a wide range of frequencies. They have become popular research tools owing to their subwavelength confinement and potential ability to perform ultrasensitive optical measurements. Driven by tremendous progress in nanofabrication techniques and ultrafast laser technologies, the applications of surface plasmon–polariton nano-optics extend beyond nanoplasmonics. In this Review, we discuss how the use of hybrid multilayer structures combining different functionalities allows the development of active plasmonic devices and new metrologies. Magneto-plasmonics, acousto-plasmonics and the generation of high-energy photoelectrons using ultrashort surface plasmon–polariton pulses are all examples of how the combination of ideas developed in these individual fields can be used to generate new knowledge, leading to a range of exciting applications in nanophotonics. Surface plasmon polaritons have become popular because of their sub-wavelength confinement and the possibility to perform ultrasensitive optical measurements. This article reviews the development of active plasmonic devices and new metrologies using hybrid multilayer structures combining with the magnetic, acoustic and ultrafast effects.

228 citations

Journal ArticleDOI
TL;DR: This comprehensive review of micro/nano acoustofluidics examines the fundamentals of piezoelectricity, piez Zoelectric materials, and transducers; revisit the basics of acoust ofluidic; and gives the reader a detailed look at recent technological advances and current scientific discussions in the discipline.
Abstract: Acoustic actuation of fluids at small scales may finally enable a comprehensive lab-on-a-chip revolution in microfluidics, overcoming long-standing difficulties in fluid and particle manipulation on-chip. In this comprehensive review, we examine the fundamentals of piezoelectricity, piezoelectric materials, and transducers; revisit the basics of acoustofluidics; and give the reader a detailed look at recent technological advances and current scientific discussions in the discipline. Recent achievements are placed in the context of classic reports for the actuation of fluid and particles via acoustic waves, both within sessile drops and closed channels. Other aspects of micro/nano acoustofluidics are examined: atomization, translation, mixing, jetting, and particle manipulation in the context of sessile drops and fluid mixing and pumping, particle manipulation, and formation of droplets in the context of closed channels, plus the most recent results at the nanoscale. These achievements will enable applications across the disciplines of chemistry, biology, medicine, energy, manufacturing, and we suspect a number of others yet unimagined. Basic design concepts and illustrative applications are highlighted in each section, with an emphasis on lab-on-a-chip applications.

189 citations

Journal ArticleDOI
TL;DR: An introduction to picosecond laser ultrasonics, a means by which gigahertz-terahertz ultrasonic waves can be generated and detected by ultrashort light pulses, which can be used to characterize materials with nanometer spatial resolution.

187 citations

01 Jul 1983
TL;DR: In this paper, the propagation of ion-acoustic solitons in a plasma with negative ions has been observed, and applied rarefactive (negative) voltage pulses break up into Solitons, whereas compressive pulses evolve into wave trains, with exactly the opposite behavior as that for a plasma composed only of positive ions.
Abstract: The propagation of ion-acoustic solitons in a plasma with negative ions has been observed. For sufficiently large concentration of negative ions, applied rarefactive (negative) voltage pulses break up into solitons, whereas compressive pulses evolve into wave trains, with exactly the opposite behavior as that for a plasma composed only of positive ions. There is a critical value of the negative-ion concentration for which a finite-amplitude pulse propagates without steepening.

142 citations