scholarly journals Beating absorption in solid-state high harmonics

2020 ◽  
Vol 3 (1) ◽  
Author(s):  
Hanzhe Liu ◽  
Giulio Vampa ◽  
Jingyuan Linda Zhang ◽  
Yu Shi ◽  
Siddharth Buddhiraju ◽  
...  
Keyword(s):  
Vacuum Ultraviolet ◽  
Crystalline Silicon ◽  
High Harmonic ◽  
Ultra Violet ◽  
Fold Increase ◽  
High Energy ◽  
High Order ◽  
Limiting Factor ◽  
X Ray ◽  
On Chip

Abstract Since the new millennium coherent extreme ultra-violet and soft x-ray radiation has revolutionized the understanding of dynamical physical, chemical and biological systems at the electron’s natural timescale. Unfortunately, coherent laser-based upconversion of infrared photons to vacuum-ultraviolet and soft x-ray high-order harmonics in gaseous, liquid and solid targets is notoriously inefficient. In dense nonlinear media, the limiting factor is strong re-absorption of the generated high-energy photons. Here we overcome this limitation by generating high-order harmonics from a periodic array of thin one-dimensional crystalline silicon ridge waveguides. Adding vacuum gaps between the ridges avoids the high absorption loss of the bulk and results in a ~ 100-fold increase of the extraction depth. As the grating period is varied, each high harmonic shows a different and marked modulation, indicating their waveguiding in the vacuum slots with reduced absorption. Looking ahead, our results enable bright on-chip coherent short-wavelength sources and may extend the usable spectral range of traditional nonlinear crystals to their absorption windows. Potential applications include on-chip chemically-sensitive spectro-nanoscopy.

Ion Implantation Defect Characterization by High-Resolution X-Ray Diffraction

1992 ◽  
Vol 262 ◽  
Author(s):  
Jos G.E. Klappe ◽  
István Bársony ◽  
Tom W. Ryan
Keyword(s):  
High Resolution ◽  
Ion Implantation ◽  
Lattice Strain ◽  
Crystalline Silicon ◽  
High Energy ◽  
Silicon Sample ◽  
Dislocation Loops ◽  
X Ray Diffraction ◽  
X Ray ◽  
Residual Defect

ABSTRACTHigh-energy ion-implantation is one of the roost critical processing steps regarding the formation of defects in mono-crystalline silicon. High- as well as low-doses implanted at various energies can result in relatively high residual defect concentrations after post-implantation annealing.Before annealing, the crystal lattice strain is mainly caused by the point defects. After annealing, the accommodation of substitutional impurities is the main origin of the residual lattice strain. High-Resolution X-ray Diffraction (HRXD) has been frequently used for the characterization of these structures. Dislocation loops formed during the high temperature step, however, cause enhanced diffuse X-ray scattering, which can dominate the measured X-ray intensity in conventional HRXD.Triple axis diffractometry is used in this study to analyze the size, type and location of defects in a boron implanted and rapid thermally annealed silicon sample.

High-Order X-Ray Raman Scattering Using Coherent Electrons from High Harmonic Generation

2006 ◽  
Vol 17 (12) ◽  
pp. 43 ◽  
Author(s):  
Nicholas L. Wagner ◽  
Andrea Wüest ◽  
Ivan P. Christov ◽  
Tenio Popmintchev ◽  
Xibin Zhou ◽  
...  
Keyword(s):  
Raman Scattering ◽  
Harmonic Generation ◽  
High Harmonic ◽  
High Harmonic Generation ◽  
High Order ◽  
X Ray

SPACE-RESOLVING VUV AND SOFT X-RAY SPECTROSCOPY IN THE TANDEM MIRROR GAMMA 10 PLASMA

2002 ◽  
Vol 09 (01) ◽  
pp. 555-559 ◽  
Author(s):  
M. YOSHIKAWA ◽  
Y. OKAMOTO ◽  
E. KAWAMORI ◽  
Y. WATANABE ◽  
C. WATABE ◽  
...  
Keyword(s):  
Vacuum Ultraviolet ◽  
Radiation Power ◽  
Emission Spectra ◽  
High Energy ◽  
Absolute Calibration ◽  
Fusion Plasmas ◽  
X Ray ◽  
Confined Plasmas ◽  
Tandem Mirror ◽  
Impurity Ions

Vacuum ultraviolet (VUV) and soft X-ray (SX) spectroscopic measurements are important means to diagnose radiation power loss, impurity ion densities and effective charge of confined plasma, Z eff , in magnetically confined plasmas such as fusion plasmas. We have constructed space- and time-resolving flat-field VUV (150–1050Å) and SX (20–350Å) spectrographs by using aberration-corrected concave gratings with varied line spacing. Absolute calibration experiments have been conducted at the Photon Factory in the High Energy Accelerator Research Organization. Absolute sensitivities of the VUV and SX spectrographs have been obtained for the two (S and P) polarization geometries. Thus, absolute intensities of emission spectra from impurity ions can be measured together with their radial distributions in plasmas. The total radiation power was determined to be less than 6 kW within ±20% of error in our normal plasma operation. Density profiles of impurity ions were reduced by using absolute emissivities of impurity lines and a collisional-radiative model. Moreover, the value of Z eff is estimated to be 1.00 in the tandem mirror GAMMA 10 plasma.

Calibration of space-resolving VUV and soft X-ray spectrographs for plasma diagnostics

1998 ◽  
Vol 5 (3) ◽  
pp. 762-765 ◽  
Author(s):  
Masayuki Yoshikawa ◽  
Naohiro Yamaguchi ◽  
Tatsuya Aota ◽  
Katsunori Ikeda ◽  
Yuuji Okamoto ◽  
...  
Keyword(s):  
Vacuum Ultraviolet ◽  
High Energy ◽  
X Ray ◽  
Confined Plasmas ◽  
High Energy Accelerator ◽  
Magnetically Confined ◽  
Flat Field ◽  
Important Means ◽  
Magnetically Confined Plasmas ◽  
Aberration Corrected

Vacuum ultraviolet (VUV) and soft X-ray measurements are important means of diagnosing impurities in magnetically confined plasmas used in fusion research. Recently, space- and time-resolving flat-field VUV (150–1050 Å) and soft X-ray (20–350 Å) spectrographs have been constructed by using aberration-corrected concave gratings with varied-spacing grooves which give a wide simultaneous spectral coverage on a microchannel-plate intensified detector. Calibration experiments have been performed at beamlines 11A and 11C at the Photon Factory of the High Energy Accelerator Research Organization. The relative efficiency of the VUV spectrograph has been measured for P-polarization geometry in the spectrograph. In the soft X-ray spectrograph, efficiencies have been obtained for several different points of irradiation on the grating along the groove direction and for two (S and P) polarization geometries.

scholarly journals Experimental evidence for the benefits of higher X-ray energies for macromolecular crystallography

2021 ◽  
Author(s):  
S. L. S. Storm ◽  
D. Axford ◽  
R. L. Owen
Keyword(s):  
High Resolution ◽  
Data Collection ◽  
High Energy ◽  
Limiting Factor ◽  
Macromolecular Crystallography ◽  
Resolution Limit ◽  
Energy Data ◽  
X Ray ◽  
Structure Solution ◽  
Unit Dose

AbstractX-ray induced radiation damage is a limiting factor for the macromolecular crystallographer and data must often be merged from many crystals to yield complete datasets for structure solution of challenging samples. Increasing the X-ray energy beyond the typical 10-15 keV range promises to provide an extension of crystal lifetime via an increase in diffraction efficiency. To date however hardware limitations have negated any possible gains. Through the first use of a Cadmium Telluride Eiger2 detector and a beamline optimised for high energy data collection, we show that at higher energies fewer crystals will be required to obtain complete data, as the diffracted intensity per unit dose increases by a factor of more than 3 between 12.4 and 25 keV. Additionally, those higher energy data provide more information, evidenced by an increase in high-resolution limit of up to 0.3 Å, pointing to a high energy future for synchrotron-based macromolecular crystallography.

scholarly journals Detecting electronic coherences by time-domain high-harmonic spectroscopy

2020 ◽  
Vol 117 (18) ◽  
pp. 9776-9781 ◽  
Author(s):  
Shicheng Jiang ◽  
Konstantin Dorfman
Keyword(s):  
Time Domain ◽  
High Harmonic ◽  
Electronic States ◽  
High Order ◽  
Laser Source ◽  
X Ray ◽  
Liouville Space ◽  
High Order Harmonic ◽  
Multiple Pulses ◽  
The Time Domain

Ultrafast spectroscopy is capable of monitoring electronic and vibrational states. For electronic states a few eV apart, an X-ray laser source is required. We propose an alternative method based on the time-domain high-order harmonic spectroscopy where a coherent superposition of the electronic states is first prepared by the strong optical laser pulse. The coherent dynamics can then be probed by the higher-order harmonics generated by the delayed probe pulse. The high nonlinearity typically modeled by the three-step mechanism introduced by Lewenstein and Corkum can serve as a recipe for generation of the coherent excitation with broad bandwidth. The main advantage of the method is that only optical (non–X-ray) lasers are needed. A semiperturbative model based on the Liouville space superoperator approach is developed for the bookkeeping of the different orders of the nonlinear response for the high-order harmonic generation using multiple pulses. Coherence between bound electronic states is monitored in the harmonic spectra from both first- and second-order responses.

X-RAY Photoemission Spectroscopic Study of Light-Induced Structural Changes in Amorphous Silicon

2000 ◽  
Vol 609 ◽  
Author(s):  
Shuran Sheng ◽  
Edward Sacher ◽  
Arthur Yelon
Keyword(s):  
Amorphous Silicon ◽  
Structural Changes ◽  
Crystalline Silicon ◽  
Light Exposure ◽  
High Energy ◽  
Binding Energies ◽  
Irradiation Effect ◽  
Incident Intensity ◽  
Illumination Time ◽  
X Ray

ABSTRACTLight- and annealing-induced structural changes in undoped hydrogenated amorphous silicon (a-Si:H), pure amorphous silicon (a-Si) and crystalline silicon (c-Si) have been investigated in detail by X-ray photoemission spectroscopy (XPS). Both the Si2s and Si2p peaks in a-Si:H films were found to shift simultaneously to lower binding energies by the same amount with illumination time, and nearly reach saturation at about 0.06 eV after one hour of light-soaking at the intensity used. In contrast to the metastable changes in electronic properties [Staebler-Wronski effect (SWE)], the light-induced shifts in both peaks are unstable even at room temperature and can be reversed by annealing with a lower activation energy than that for the SWE. The absence of metastable XPS changes in pure a-Si and c-Si suggests that hydrogen is actively involved in the light-induced structural changes. Furthermore, visible light exposure produces XPS changes in a-Si:H less effectively than X-ray irradiation, despite its much higher incident intensity, indicating a high-energy photon irradiation effect. Our present results suggest that essentially the whole Si network structure is affected by light-soaking or X-ray irradiation, and becomes more stable after repeated irradiation-annealing training. These structural changes may be an independent metastable phenomenon or a precursor process of the SWE.

scholarly journals EUV and Hard X-ray Hartmann Wavefront Sensing for Optical Metrology, Alignment and Phase Imaging

Sensors ◽  
2021 ◽  
Vol 21 (3) ◽  
pp. 874
Author(s):  
Ombeline de La Rochefoucauld ◽  
Guillaume Dovillaire ◽  
Fabrice Harms ◽  
Mourad Idir ◽  
Lei Huang ◽  
...  
Keyword(s):  
High Performance ◽  
High Harmonic ◽  
Ultra Violet ◽  
Phase Imaging ◽  
Wavefront Sensors ◽  
X Ray ◽  
X Ray Imaging ◽  
Wide Range ◽  
Automatic Alignment ◽  
Euv Lasers

For more than 15 years, Imagine Optic have developed Extreme Ultra Violet (EUV) and X-ray Hartmann wavefront sensors for metrology and imaging applications. These sensors are compatible with a wide range of X-ray sources: from synchrotrons, Free Electron Lasers, laser-driven betatron and plasma-based EUV lasers to High Harmonic Generation. In this paper, we first describe the principle of a Hartmann sensor and give some key parameters to design a high-performance sensor. We also present different applications from metrology (for manual or automatic alignment of optics), to soft X-ray source optimization and X-ray imaging.

scholarly journals Generation of high-flux soft X-ray high harmonics driven by loosely focused TW-class infrared pulses

2019 ◽  
Vol 205 ◽  
pp. 02012
Author(s):  
Kotaro Nishimura ◽  
Yuxi Fu ◽  
Akira Suda ◽  
Katsumi Midorikawa ◽  
J. Takahashi Eiji
Keyword(s):  
High Energy ◽  
High Order ◽  
High Flux ◽  
Femtosecond Pulses ◽  
X Ray ◽  
Experimental Strategy ◽  
High Harmonics

We develop an experimental strategy for generating high-flux soft x-ray high-order harmonics (HH) driven by loosely focused high-energy infrared femtosecond pulses. Strong soft x-ray HHs are generated in a long Ne medium.

scholarly journals Bright High-Order Harmonic Generation around 30 nm Using Hundred-Terawatt-Level Laser System for Seeding Full Coherent XFEL

2018 ◽  
Vol 8 (9) ◽  
pp. 1446 ◽  
Author(s):  
Luyao Zhang ◽  
Yinghui Zheng ◽  
Guicun Li ◽  
Zhengmao Jia ◽  
Yanyan Li ◽  
...  
Keyword(s):  
Harmonic Generation ◽  
Beam Quality ◽  
Laser System ◽  
High Harmonic ◽  
High Order ◽  
Laser Source ◽  
High Order Harmonic Generation ◽  
X Ray ◽  
High Order Harmonic ◽  
Level Laser

In the past few years, the laser wakefield acceleration (LWFA) electron is a hot topic. One of its applications is to produce soft X-ray free-electron laser (XFEL). During this process, high harmonic generation (HHG) is a potential seed. To decrease the timing jitter between LWFA and HHG, it is better for them to come from the same laser source. We have experimentally investigated bright high-order harmonic generation with a 200-terawatt (TW)/1-Hz Ti: Sapphire laser system. By using the loosely focused method and optimizing the phase-matching conditions, we have obtained bright high-order harmonics around 30 nm. Output energy of the 29th harmonic (27.6 nm) reaches as high as 100 nJ per pulse, and the harmonic beam divergence is estimated to be 0.3 mrad in a full width at half maximum (FWHM). Although the hundred-TW-level laser system has the problems of poor beam quality and shot-to-shot energy fluctuation for HHG, the generated soft X-ray (~30 nm) sources can also have good stability by carefully optimizing the laser system.

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