Results 251 to 260 of about 496,345 (292)

Nonlinear Beam Shaping in Domain Engineered Ferroelectric Crystals

Advanced Materials, 2019
AbstractDomain engineered ferroelectric crystals are a type of microstructure functional material that is used widely in the area of nonlinear optics. Herein, research processes in the area of nonlinear beam shaping using domain engineered crystals in the past decade are reviewed.
Xiaopeng Hu, Yong Zhang, Shining Zhu
openaire   +2 more sources

Beam-TasNet: Time-domain Audio Separation Network Meets Frequency-domain Beamformer

ICASSP 2020 - 2020 IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP), 2020
Recent studies have shown that acoustic beamforming using a microphone array plays an important role in the construction of high-performance automatic speech recognition (ASR) systems, especially for noisy and overlapping speech conditions. In parallel with the success of multichannel beamforming for ASR, in the speech separation field, the time-domain
Tsubasa Ochiai, Marc Delcroix, Rintaro Ikeshita, Keisuke Kinoshita, Tomohiro Nakatani, Shoko Araki   +5 more
openaire   +1 more source

Time-domain finite-difference beam propagation method

IEEE Photonics Technology Letters, 1999
A new technique to model the behavior of pulsed optical beams in waveguides is proposed and analyzed. The technique is an extension of the traditional continuous-wave beam propagation method (BPNI) to include time dependence, therefore called the time-domain BPM (TD-BPM). The method was tested using different waveguide examples and it is concluded that
Masoudi, H.M., AlSunaidi, M.A., Arnold, J.M.   +2 more
openaire   +1 more source

Time-domain analysis of photon beams

Proceedings of the Physical Society, 1966
The analysis of photon beams in terms of the time intervals between photon counts is discussed; in particular, the cases of beats and of sinusoidal amplitude modulation are considered.
openaire   +1 more source

Beam-based time-domain tomographic inverse scattering

2019 International Conference on Electromagnetics in Advanced Applications (ICEAA), 2019
We present a novel beam-based theory for local time-dependent tomographic inverse scattering. The formulation is structured upon the recently introduced concept of “pulsed-beam frame” (PBF). The PBF is a properly constructed phase-space set of iso-diffracting pulsed-beam waves (ID-PB) that constitutes a frame everywhere in the propagation domain.
Ram Tuvi, Ehud Heyman, Timor Melamed
openaire   +1 more source

Parallel domain decomposition methods for beam-tracing

Pollack Periodica, 2012
In this paper, a comparison of parallel beam-tracing methods is presented and an original parallel domain decomposition method is proposed to solve numerical acoustic problems. A hybrid method between the ray-tracing and the beam-tracing method is first introduced.
Magoules, F., Venet, C.
openaire   +3 more sources

Domain inversion in LiTaO3 by electron beam

Applied Physics Letters, 1992
Domain inversion in Z-cut LiTaO3 by injecting electrons into negative C face was observed but no domain inversion was observed on injecting electrons on positive C face. At low electron-beam currents, small multidomains are observed. At a scan rate of 2 μm/s and beam current of 100 pA, a domain width of about 6 μm was obtained.
Wei-Yung Hsu, Mool C. Gupta
openaire   +1 more source

A Beam Domain Selection Method Based on the Conventional Beam Forming

Applied Mechanics and Materials, 2014
Beam forming technology is an important content in the study of underwater target positioning, can directly use beam forming technology to identify the target direction, but can be by beam forming of target signal enhancement, and then to deal with the enhanced signal.
openaire   +1 more source

Experimental Identification Technique of Nonlinear Beams in Time Domain

Nonlinear Dynamics, 1997
Abstract In previous papers the authors proposed a new experimental identification technique applicable to elastic structures. The proposed technique is based on the principle of harmonic balance, and can be classified as the frequency domain technique. The technique requires the excitation force to be periodic.
Yasuda, K., Kamiya, K.
openaire   +2 more sources

True beam smoothing in the fractional Fourier transform domain

Journal of Modern Optics, 2003
Abstract The design of a diffractive optical element (DOE) for true beam smoothing in the fractional Fourier transform domain is described. Based on the Fresnel integrals, the intensity distribution on the output plane is calculated accurately and the discretization error of the spherical phase factor is avoided.
Tan Qiaofeng, Van Yingbai, Jin Guofan, Xu Duanyi   +3 more
openaire   +1 more source