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Wootton KP, McNeur J, Leedle KJ. Dielectric Laser Accelerators: Designs, Experiments, and Applications. ACTA ACUST UNITED AC 2017. [DOI: 10.1142/s179362681630005x] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Novel laser-powered accelerating structures at the miniaturized scale of an optical wavelength [Formula: see text] open a pathway to high repetition rate, attosecond scale electron bunches that can be accelerated with gradients exceeding 1 GeV/m. Although the theoretical and computational study of dielectric laser accelerators dates back many decades, recently the first experimental realizations of this novel class of accelerators have been demonstrated. We review recent developments in fabrication, testing, and demonstration of these micron scale devices. In particular, prospects for applications of this accelerator technology are evaluated.
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Affiliation(s)
- K. P. Wootton
- SLAC National Accelerator Laboratory, 2575 Sand Hill Rd, Menlo Park, California 94025, USA
| | - J. McNeur
- Department of Physics, Friedrich-Alexander-Universität Erlangen-Nürnberg, Staudtstrasse 1, 91058 Erlangen, Germany
| | - K. J. Leedle
- Department of Electrical Engineering, Stanford University, 450 Serra Mall, Stanford, California 94305, USA
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Jacob G, Groot-Berning K, Wolf S, Ulm S, Couturier L, Dawkins ST, Poschinger UG, Schmidt-Kaler F, Singer K. Transmission Microscopy with Nanometer Resolution Using a Deterministic Single Ion Source. PHYSICAL REVIEW LETTERS 2016; 117:043001. [PMID: 27494469 DOI: 10.1103/physrevlett.117.043001] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/03/2015] [Indexed: 06/06/2023]
Abstract
We realize a single particle microscope by using deterministically extracted laser-cooled ^{40}Ca^{+} ions from a Paul trap as probe particles for transmission imaging. We demonstrate focusing of the ions to a spot size of 5.8±1.0 nm and a minimum two-sample deviation of the beam position of 1.5 nm in the focal plane. The deterministic source, even when used in combination with an imperfect detector, gives rise to a fivefold increase in the signal-to-noise ratio as compared with conventional Poissonian sources. Gating of the detector signal by the extraction event suppresses dark counts by 6 orders of magnitude. We implement a Bayes experimental design approach to microscopy in order to maximize the gain in spatial information. We demonstrate this method by determining the position of a 1 μm circular hole structure to a precision of 2.7 nm using only 579 probe particles.
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Affiliation(s)
- Georg Jacob
- QUANTUM, Institut für Physik, Universität Mainz, Staudingerweg 7, 55128 Mainz, Germany
| | - Karin Groot-Berning
- QUANTUM, Institut für Physik, Universität Mainz, Staudingerweg 7, 55128 Mainz, Germany
| | - Sebastian Wolf
- QUANTUM, Institut für Physik, Universität Mainz, Staudingerweg 7, 55128 Mainz, Germany
| | - Stefan Ulm
- QUANTUM, Institut für Physik, Universität Mainz, Staudingerweg 7, 55128 Mainz, Germany
| | - Luc Couturier
- QUANTUM, Institut für Physik, Universität Mainz, Staudingerweg 7, 55128 Mainz, Germany
| | - Samuel T Dawkins
- QUANTUM, Institut für Physik, Universität Mainz, Staudingerweg 7, 55128 Mainz, Germany
| | - Ulrich G Poschinger
- QUANTUM, Institut für Physik, Universität Mainz, Staudingerweg 7, 55128 Mainz, Germany
| | | | - Kilian Singer
- QUANTUM, Institut für Physik, Universität Mainz, Staudingerweg 7, 55128 Mainz, Germany
- Institut für Physik, Universität Kassel, Heinrich-Plett-Straße 40, 34132 Kassel, Germany
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Signal-to-noise in femtosecond electron diffraction. Ultramicroscopy 2015; 159 Pt 1:19-25. [PMID: 26241301 DOI: 10.1016/j.ultramic.2015.07.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2015] [Revised: 07/16/2015] [Accepted: 07/21/2015] [Indexed: 11/22/2022]
Abstract
Pump-probe electron diffraction can directly record atomic-scale motion within molecules or materials. However, the available current in femtosecond experiments is limited, making it challenging to reach the sensitivity required for detecting the fastest structural dynamics, which are encoded in time-dependent diffraction intensities. Here we present a unified analysis of signal-to-noise for an ultrafast electron diffraction apparatus. We characterize the noise of realistic ultrafast electron sources and detectors, test the performance on crystalline and polycrystalline samples and discuss practical approaches for improving measurement sensitivity. The analysis is found sufficient to predict the achievable signal-to-noise ratio in pump-probe electron diffraction before actually starting an investigation.
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Kealhofer C, Klopfer BB, Skulason GE, Juffmann T, Foreman SM, Kasevich MA. Ultrafast oscilloscope based on laser-triggered field emitters. OPTICS LETTERS 2015; 40:260-263. [PMID: 25679859 DOI: 10.1364/ol.40.000260] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Laser-triggered electron emission from sharp metal tips has been demonstrated in recent years as a high brightness, ultrafast electron source. Its possible applications range from ultrafast electron microscopy to laser-based particle accelerators to electron interferometry. The ultrafast nature of the emission process allows for the sampling of an instantaneous radio frequency (RF) voltage that has been applied to a field emitter. For proof-of-concept, we use an RF signal derived from our laser's repetition rate, mapping a 9.28 GHz signal in 22.4 fs steps with 28 mv accuracy.
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Krüger M, Schenk M, Förster M, Thomas S, Wachter G, Lemell C, Burgdörfer J, Hommelhoff P. Attosecond physics at a nanoscale metal tip. EPJ WEB OF CONFERENCES 2013. [DOI: 10.1051/epjconf/20134101005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Bornmann B, Mingels S, Dams F, Prommesberger C, Schreiner R, Lützenkirchen-Hecht D, Müller G. Electron spectrometer in adjustable triode configuration for photo-induced field emission measurements. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2012; 83:013302. [PMID: 22299940 DOI: 10.1063/1.3673475] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
We have constructed a new ultrahigh vacuum apparatus with a triode configuration for the systematic investigation of photo-induced field emission (PFE) from metallic or semiconducting cathodes. These are exposed to electric fields up to 400 MV∕m and laser irradiation by means of hole or mesh gates. Cathodes and gates are in situ exchangeable and adjustable with high precision to ensure a homogeneous extraction of electrons which are partially transmitted to the fixed electron spectrometer. Its hemispherical sector analyzer provides an energy resolution limit of 8 meV. The commissioning of the measurement system has been performed with a tungsten needle. Its temperature showed up in the high-energy tail of the electron spectrum, while its work function was derived from the spectral low-energy part combined with the integral current-voltage curve. First PFE measurements on B-doped Si-tip arrays yielded a small field emission current increase under green laser illumination. A shift and splitting of the energy spectra was observed which revealed different emission regimes as well as the photosensitivity of the cathode due to carrier excitation into the conduction band. For the full exploitation of the PFE system, a tunable laser over a wide eV-range is required.
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Affiliation(s)
- B Bornmann
- FB C Physics Department, University of Wuppertal, Wuppertal, Germany.
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NiewieczerzaŁ D, Oleksy C, Szczepkowicz A. Multi-scale simulations of field ion microscopy images—Image compression with and without the tip shank. Ultramicroscopy 2012; 112:1-9. [DOI: 10.1016/j.ultramic.2011.10.007] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2011] [Revised: 10/03/2011] [Accepted: 10/14/2011] [Indexed: 10/16/2022]
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Schenk M, Krüger M, Hommelhoff P. Strong-field above-threshold photoemission from sharp metal tips. PHYSICAL REVIEW LETTERS 2010; 105:257601. [PMID: 21231628 DOI: 10.1103/physrevlett.105.257601] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/13/2010] [Revised: 11/18/2010] [Indexed: 05/24/2023]
Abstract
We present energy-resolved measurements of electron emission from sharp metal tips driven with low energy pulses from a few-cycle laser oscillator. We observe above-threshold photoemission with a photon order of up to 9. At a laser intensity of ∼ 2 × 10(11) W/cm2 the suppression of the lowest order peak occurs, indicating the onset of strong-field effects. We also observe peak shifting linearly with intensity, with a slope of around -1.0 eV/(10(12) W/cm2). We attribute the magnitude of the laser field effects to field enhancement taking place at the tip's surface.
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Affiliation(s)
- Markus Schenk
- Max-Planck-Institut für Quantenoptik, Hans-Kopfermann-Str. 1, 85748 Garching, Germany
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Abstract
Visualization of atomic-scale structural motion by ultrafast electron diffraction and microscopy requires electron packets of shortest duration and highest coherence. We report on the generation and application of single-electron pulses for this purpose. Photoelectric emission from metal surfaces is studied with tunable ultraviolet pulses in the femtosecond regime. The bandwidth, efficiency, coherence, and electron pulse duration are investigated in dependence on excitation wavelength, intensity, and laser bandwidth. At photon energies close to the cathode's work function, the electron pulse duration shortens significantly and approaches a threshold that is determined by interplay of the optical pulse width and the acceleration field. An optimized choice of laser wavelength and bandwidth results in sub-100-fs electron pulses. We demonstrate single-electron diffraction from polycrystalline diamond films and reveal the favorable influences of matched photon energies on the coherence volume of single-electron wave packets. We discuss the consequences of our findings for the physics of the photoelectric effect and for applications of single-electron pulses in ultrafast 4D imaging of structural dynamics.
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Image deformation in field ion microscopy of faceted crystals. Ultramicroscopy 2010; 110:234-41. [DOI: 10.1016/j.ultramic.2009.12.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2009] [Revised: 11/23/2009] [Accepted: 12/01/2009] [Indexed: 11/23/2022]
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