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An experimental study of laser pulse duration influence on the terahertz emission during single-color filamentation is carried out. It is shown that for each terahertz frequency there is an optimal laser pulse duration providing maximal…

The reconstructed images from the Synthetic Aperture Radar (SAR) data suffer from multiplicative noise as well as low contrast level. These two factors impact the quality of the SAR images significantly and prevent any attempt to extract…

Image and Video Processing · Electrical Eng. & Systems 2024-12-05 Shahrokh Hamidi

The exoplanetary science through direct imaging and spectroscopy will largely expand with the forthcoming development of new instruments at the VLT (SPHERE), Gemini (GPI), Subaru (HiCIAO), and Palomar (Project 1640) observatories. All these…

Instrumentation and Methods for Astrophysics · Physics 2015-05-27 P. Martinez , E. Aller-Carpentier , M. Kasper , A. Boccaletti , C. Dorrer , J. Baudrand

We report a straightforward method to control main spatio-temporal couplings in a CPA laser chain system using a specially designed chromatic doublet in a divergent beam configuration. The centering of the doublet allows for the control of…

We introduce a charge coupled device (CCD) camera based detection scheme in dynamic light scattering that provides information on the single-scattered auto-correlation function even for fairly turbid samples. It is based on the single…

Soft Condensed Matter · Physics 2009-11-11 Pavel Zakharov , Suresh Bhat , Peter Schurtenberger , Frank Scheffold

Temporal imaging systems are outstanding tools for single-shot observation of optical signals that have irregular and ultrafast dynamics. They allow long time windows to be recorded with femtosecond resolution, and do not rely on complex…

Contrastive learning, as a self-supervised learning paradigm, becomes popular for Multivariate Time-Series (MTS) classification. It ensures the consistency across different views of unlabeled samples and then learns effective…

Machine Learning · Computer Science 2024-01-11 Yucheng Wang , Yuecong Xu , Jianfei Yang , Min Wu , Xiaoli Li , Lihua Xie , Zhenghua Chen

We present time-resolved X-ray diffraction measurements using advanced timing schemes that provide high temporal resolution while also maintaining a high flux in the X-ray probe beam. The method employs patterned probe pulse sequences that…

Ptychography provides high dose efficiency images that can reveal light elements next to heavy atoms. However, despite ptychography having an otherwise single signed contrast transfer function, contrast reversals can occur when the…

Applied Physics · Physics 2023-06-16 C. Gao , C. Hofer , T. J. Pennycook

Pulse-compression is a correlation-based measurement technique successfully used in many NDE applications to increase the SNR in the presence of huge noise, strong signal attenuation or when high excitation levels must be avoided. In…

Signal Processing · Electrical Eng. & Systems 2024-05-02 Marco Ricci , Rocco Zito , Stefano Laureti

The highly transient nature of shock loading and pronounced microstructure effects on dynamic materials response call for {\it in situ}, temporally and spatially resolved, x-ray-based diagnostics. Third-generation synchrotron x-ray sources…

Other Condensed Matter · Physics 2015-06-04 S. N. Luo , B. J. Jensen , D. E. Hooks , K. Fezzaa , K. J. Ramos , J. D. Yeager , K. Kwiatkowski , 1 , T. Shimada

The attenuation of fringe contrast in a Ramsey interferometer induced by the atom-field interaction is analyzed. We show that short-time power series expansion is not the proper tool to find the relevant time scale for such process.…

Quantum Physics · Physics 2012-08-13 A. R. Bosco de Magalhães , Adélcio C. Oliveira

Ultrafast electron microscopy provides a movie-like access to structural dynamics of materials in space and time, but fundamental atomic motions or electron dynamics are, so far, too quick to be resolved. Here we report the all-optical…

Optics · Physics 2024-02-27 J. Kuttruff , D. Nabben , A. C. Zimmermann , A. Ryabov , P. Baum

For conventional imaging, the imaging resolution limit is given by the Rayleigh criterion. Exploiting the prior knowledge of imaging object's sparsity and fixed optical system, imaging beyond the conventional Rayleigh limit, which is backed…

Optics · Physics 2014-05-30 Wenlin Gong , Shensheng Han

Terahertz time-domain spectroscopy (THz-TDS) employs sub-picosecond pulses to probe dielectric properties of materials giving as a result a 3-dimensional hyperspectral data cube. The spatial resolution of THz images is primarily limited by…

Attosecond transient absorption spectroscopy has thus far been lacking the capability to simultaneously characterize the intense laser pulses at work within a time-resolved quantum-dynamics experiment. However, precise knowledge of these…

We present a simple and direct method for measuring laser chirp rate, i.e., group delay dispersion (GDD) of ultrashort laser pulses at power levels compatible with single-quantum-emitter excitation. Traditional pulse characterization…

Event cameras have recently gained significant traction since they open up new avenues for low-latency and low-power solutions to complex computer vision problems. To unlock these solutions, it is necessary to develop algorithms that can…

Computer Vision and Pattern Recognition · Computer Science 2023-09-28 Federico Paredes-Vallés , Kirk Y. W. Scheper , Christophe De Wagter , Guido C. H. E. de Croon

We demonstrate optical pump/THz probe (OPTP) spectroscopy with a variable external magnetic field (0-9 T) in which the time-dependent THz signal is measured by echelon-based single-shot detection at a 1 kHz repetition rate. The method…

Speech Emotion Recognition (SER) is a challenging task due to limited data and blurred boundaries of certain emotions. In this paper, we present a comprehensive approach to improve the SER performance throughout the model lifecycle,…

Audio and Speech Processing · Electrical Eng. & Systems 2023-09-01 Xuechen Wang , Shiwan Zhao , Yong Qin