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Previous research on late-reverberation modeling has mainly focused on exponentially decaying room impulse responses, whereas methods for accurately modeling non-exponential reverberation remain challenging. This paper extends the…

Audio and Speech Processing · Electrical Eng. & Systems 2024-04-02 Jon Fagerström , Sebastian J. Schlecht , Vesa Välimäki

Intelligent reflecting surface (IRS) has garnered growing interest and attention due to its potential for facilitating and supporting wireless communications and sensing. This paper studies a semi-passive IRS-enabled sensing system, where…

Signal Processing · Electrical Eng. & Systems 2024-02-06 Qiaoyan Peng , Qingqing Wu , Wen Chen , Shaodan Ma , Ming-Min Zhao , Octavia A. Dobre

Micro-Laue diffraction and simultaneous rainbow-filtered micro-diffraction were used to measure accurately the full strain tensor and the lattice orientation distribution at the sub-micron scale in highly strained, suspended Ge…

Perfect lensing using negative refractive index materials and radiationless electromagnetic interference both provide extreme subwavelength focusing by "amplifying" evanescent wave components that are usually lost. This paper provides a…

Optics · Physics 2015-06-03 Reuven Gordon

Control of optical properties of materials by tuning their refractive index can revolutionize the current state-of-the-art technology to manipulate light propagation in the high loss media. Here we demonstrate active optical tuning of the…

Optics · Physics 2025-06-25 Elif Ozturk , Hira Asif , Mehmet Gunay , Mehmet Emre Tasgin , Ramazan Sahin

Intelligent reflecting surfaces (IRSs) have emerged as a promising technology to improve the efficiency of wireless communication systems. However, passive IRSs suffer from the ``multiplicative fading" effect, because the transmit signal…

Information Theory · Computer Science 2023-05-11 Zeyan Zhuang , Xin Zhang , Dongfang Xu , Shenghui Song

We study phase conjugation in a nonlinear composite slab when the counter propagating pump waves are completely absorbed by means of coherent perfect absorption. Under the undepleted pump approximation the coupling constant and the phase…

Optics · Physics 2016-11-29 K. Nireekshan Reddy , Achanta Venu Gopal , S. Dutta Gupta

We establish a new approach for pump-probe simulations of metallic metamaterials coupled to the gain materials. It is of vital importance to understand the mechanism of the coupling of metamaterials with the gain medium. Using a four-level…

Optics · Physics 2012-06-25 Zhixiang Huang , Thomas Koschny , Costas M. Soukoulis

Electrostatic gating offers elegant ways to simultaneously strain and dope atomically thin membranes. Here, we report on a detailed \textit{in situ} Raman scattering study on graphene, suspended over a Si/SiO$_2$ substrate. In such a…

Mesoscale and Nanoscale Physics · Physics 2017-01-30 Dominik Metten , Guillaume Froehlicher , Stéphane Berciaud

In the framework of a one-dimensional model with a tightly localized self-attractive nonlinearity, we study the formation and transfer (dragging) of a trapped mode by "nonlinear tweezers", as well as the scattering of coherent linear wave…

Pattern Formation and Solitons · Physics 2015-06-03 Kai Li , P. G. Kevrekidis , Boris A. Malomed , D. J. Frantzeskakis

We consider the reflection-transmission problem in a waveguide with obstacle. At certain frequencies, for some incident waves, intensity is perfectly transmitted and the reflected field decays exponentially at infinity. In this work, we…

Numerical Analysis · Mathematics 2018-01-29 Anne-Sophie Bonnet-Ben Dhia , Lucas Chesnel , Vincent Pagneux

Graphene plasmonic nanostructures enable subwavelength confinement of electromagnetic energy from the mid-infrared down to the terahertz frequencies. By exploiting the spectrally varying light scattering phase at vicinity of the resonant…

We demonstrate that a transformation device can be emulated using a gradient-index waveguide. The effective index of the waveguide is spatially varied by tailoring a gradient thickness dielectric waveguide. Based on this technology, we…

Optics · Physics 2015-06-05 Y. Wang , C. Sheng , H. Liu , Y. J. Zheng , C. Zhu , S. M. Wang , S. N. Zhu

In this letter, we design passive beamforming in an intelligent reflecting surface (IRS) assisted multiple-user wireless network. Two different scenarios are considered, namely, multicasting and multi-user downlink transmission. We optimize…

Information Theory · Computer Science 2020-07-22 Ke-Wen Huang , Hui-Ming Wang

We demonstrate the in situ detection of cold 87 Rb atoms near a dielectric surface using the absorption of a weak, resonant evanescent wave. We have used this technique in time of flight experiments determining the density of atoms falling…

Graphene is a very attractive material for broadband photodetection in hyperspectral imaging and sensing systems. However, its potential use has been hindered by tradeoffs between the responsivity, bandwidth, and operation speed of existing…

Applied Physics · Physics 2017-10-03 Semih Cakmakyapan , Ping Keng Lu , Aryan Navabi , Mona Jarrahi

We investigate dispersion and absorption properties of a weak probe field in a four level atomic system through interacting dark resonances. We show that two narrow peaks appears in the optical spectra due to the presence of interacting…

Quantum Physics · Physics 2010-01-12 Kh. Saaidi , S. Dehnar Sydid , S. W. Rabiei

We propose an efficient approach for actively controlling the Rabi oscillations in emitter-cavity hybrids based on the presence of an element with optical gain. Inspired by recent developments in parity-time ($\mathcal{PT}$)-symmetry…

We have theoretically investigated optical tweezing of gain-functionalized microspheres using a highly focused single beam in the nonparaxial regime. We employ the Mie-Debye theory of optical tweezers to calculate the optical force acting…

Optics · Physics 2021-10-27 R. Ali , R. S. Dutra , F. A. Pinheiro , P. A. Maia Neto

We extend the ideas of the recently proposed perfect lens [J.B. Pendry, Phys. Rev. Lett. {\bf 85}, 3966 (2000)] to an alternative structure. We show that a slab of a medium with negative refractive index bounded by media of different…

Condensed Matter · Physics 2009-11-07 S. Anantha Ramakrishna , J. B. Pendry , D. Schurig , D. R. Smith , S. Schultz