Strong-field response time and its implications on attosecond measurement

Abstract Using single-shot velocity map imaging technique, explosion imaging of different ion species ejected from 50 nm SiO2 nanoparticles are obtained excitedly by strong near-infrared and ultraviolet femtosecond laser fields. Characteristic momentum distributions showing forward emission of the ions at low excitation intensities and shock wave behaviors at high intensities are observed. When the excitation intensity is close to the dissociative ionization threshold of the surface molecules, the resulting ion products can be used to image the instant near-field distributions. The underlying dynamics of shock formation are simulated by using a Coulomb explosion model. Our results allow one to distinguish the ultrafast strong-field response of various molecular species in nanosystems and will open a new way for further exploration of the underlying dynamics of laser-and-nanoparticle interactions.

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Terahertz strong-field physics in light-emitting diodes for terahertz detection and imaging

Communications Physics ◽

10.1038/s42005-020-00508-w ◽

2021 ◽

Vol 4 (1) ◽

Author(s):

Chen Ouyang ◽

Shangqing Li ◽

Jinglong Ma ◽

Baolong Zhang ◽

Xiaojun Wu ◽

...

Keyword(s):

Response Time ◽

Light Emitting Diodes ◽

Impact Ionization ◽

Strong Field ◽

Schottky Contact ◽

Cost Effective ◽

Light Emitting ◽

Thz Detectors ◽

Strong Field Physics ◽

Temperature Operating

AbstractIntense terahertz (THz) electromagnetic fields have been utilized to reveal a variety of extremely nonlinear optical effects in many materials through nonperturbative driving of elementary and collective excitations. However, such nonlinear photoresponses have not yet been obeserved in light-emitting diodes (LEDs), let alone employing them as fast, cost-effective, compact, and room-temperature-operating THz detectors and cameras. Here, we report ubiquitously available LEDs exhibiting photovoltaic signals of ~0.8 V and ~2 ns response time with signal-to-noise ratios of ~1300 when being illuminated by THz field strengths ~240 kV/cm. We also demonstrated THz-LED detectors and camera prototypes. These unorthodox THz detectors exhibited high responsivities (>1 kV/W) with response time four orders of magnitude shorter than those of pyroelectric detectors. The mechanism was attributed to THz-field-induced impact ionization and Schottky contact. These findings not only help deepen our understanding of strong THz field-matter interactions but also contribute to the applications of strong-field THz diagnosis.

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Signatures of molecular structure in the strong-field response of aligned molecules

Journal of Modern Optics ◽

10.1080/09500340410001731039 ◽

2005 ◽

Vol 52 (2-3) ◽

pp. 465-478 ◽

Cited By ~ 25

Author(s):

M. Lein ◽

R. De Nalda ◽

E. Heesel ◽

N. Hay ◽

E. Springate ◽

...

Keyword(s):

Molecular Structure ◽

Strong Field ◽

Field Response

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High resolution STEM imaging study on high Tc superconductor YBa2CuaO7-x

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100106478 ◽

1988 ◽

Vol 46 ◽

pp. 882-883

Author(s):

H.-J. Ou ◽

J. M. Cowley

Keyword(s):

Crystal Structure ◽

High Resolution ◽

Grain Boundary ◽

Strong Field ◽

Imaging Study ◽

Structure Defects ◽

High Tc ◽

High Tc Superconductor ◽

Diffraction Patterns ◽

Lattice Planes

Using the dedicate VG-HB5 STEM microscope, the crystal structure of high Tc superconductor of YBa2Cu3O7-x has been studied via high resolution STEM (HRSTEM) imaging and nanobeam (∽3A) diffraction patterns. Figure 1(a) and 2(a) illustrate the HRSTEM image taken at 10' times magnification along [001] direction and [100] direction, respectively. In figure 1(a), a grain boundary with strong field contrast is seen between two crystal regions A and B. The grain boundary appears to be parallel to a (110) plane, although it is not possible to determine [100] and [001] axes as it is in other regions which contain twin planes [3]. Following the horizontal lattice lines, from left to right across the grain boundary, a lattice bending of ∽4° is noticed. Three extra lattice planes, indicated by arrows, were found to terminate at the grain boundary and form dislocations. It is believed that due to different chemical composition, such structure defects occur during crystal growth. No bending is observed along the vertical lattice lines.

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Temporal Prediction Errors Affect Short-Term Memory Scanning Response Time

Experimental Psychology (formerly Zeitschrift für Experimentelle Psychologie) ◽

10.1027/1618-3169/a000339 ◽

2016 ◽

Vol 63 (6) ◽

pp. 333-342

Author(s):

Roberto Limongi ◽

Angélica M. Silva

Keyword(s):

Response Time ◽

Short Term Memory ◽

Estimation Error ◽

Predictive Coding ◽

Time Estimation ◽

Prediction Errors ◽

Memory Scanning ◽

Short Term ◽

Term Memory ◽

Temporal Prediction

Abstract. The Sternberg short-term memory scanning task has been used to unveil cognitive operations involved in time perception. Participants produce time intervals during the task, and the researcher explores how task performance affects interval production – where time estimation error is the dependent variable of interest. The perspective of predictive behavior regards time estimation error as a temporal prediction error (PE), an independent variable that controls cognition, behavior, and learning. Based on this perspective, we investigated whether temporal PEs affect short-term memory scanning. Participants performed temporal predictions while they maintained information in memory. Model inference revealed that PEs affected memory scanning response time independently of the memory-set size effect. We discuss the results within the context of formal and mechanistic models of short-term memory scanning and predictive coding, a Bayes-based theory of brain function. We state the hypothesis that our finding could be associated with weak frontostriatal connections and weak striatal activity.

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