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Related papers: Universal Features of Terahertz Absorption in Diso…

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Enhancing absorption in optically thin semiconductors is the key in the development of high-performance optical and optoelectronic devices. In this paper, we resort to the concept of degenerate critical coupling and design an ultra-thin…

Optics · Physics 2021-11-23 Wenya Chen , Xing Wang , Junyi Duan , Chaobiao Zhou , Tingting Liu , Shuyuan Xiao

We consider frequency-domain acoustic scattering at a homogeneous star-shaped penetrable obstacle, whose shape is uncertain and modelled via a radial spectral parameterization with random coefficients. Using recent results on the stability…

Numerical Analysis · Mathematics 2025-04-14 Ralf Hiptmair , Christoph Schwab , Euan A. Spence

An arbitrary optical waveform can be synthesized by complex-frequency waves as well as by realfrequency harmonic waves. While single complex-frequency wave with exponentially rising waveform can be perfectly absorbed in lossless structures.…

Optics · Physics 2025-12-22 Zhaohua Tian , Yu Tian , Yadi Niu , Qi Liu , Zihan Mo , Haoyang Zhang , Qihuang Gong , Ying Gu

We consider a non-Hermitian medium with a gain and loss symmetric, exponentially damped potential distribution to demonstrate different scattering features analytically. The condition for critical coupling (CC) for unidirectional wave and…

Quantum Physics · Physics 2015-06-19 Mohammad Hasan , Ananya Ghatak , Bhabani Prasad Mandal

The advent of novel nonlinear materials has stirred unprecedented interest in exploring the use of temporal inhomogeneities to achieve novel forms of wave control, amidst the greater vision of engineering metamaterials across both space and…

Optics · Physics 2022-11-24 Emanuele Galiffi , Shixiong Yin , Andrea Alù

We present experimental results on the optical absorption spectra of epitaxial graphene from the visible to the terahertz (THz) frequency range. In the THz range, the absorption is dominated by intraband processes with a frequency…

It has been established that the low frequency quasi-localized modes of amorphous solids at zero temperature exhibit universal density of states, depending on the frequencies as $D(\omega) \sim \omega^4$. It remains an open question whether…

Statistical Mechanics · Physics 2021-03-03 Prasenjit Das , Itamar Procaccia

The polarization direction of an electromagnetic field changes and eventually reaches a steady state when propagating through a birefringent material with off axis absorption or gain. The steady state orientation direction depends on the…

Atomic Physics · Physics 2016-01-27 Mahmood Sabooni , Adam N. Nilsson , Gerhard Kristensson , Lars Rippe

We demonstrate the existence of a frequency band exhibiting acoustic transparency in 2D and 3D dense granular suspensions, enabling the transmission of a low-frequency ballistic wave excited by a high-frequency broadband ultrasound pulse.…

We report on interferometric autocorrelation measurements of broadband supercontinuum light in the anomalous dispersion regime using two-photon absorption in a GaP photodetector. The method is simple, low-cost, and provides a direct measure…

Absorption of light is directly associated with dissipative processes in a material. In suitably tailored resonators, a specific level of dissipation can support coherent perfect absorption, the time-reversed analogue of lasing, which…

Optics · Physics 2017-10-26 Denis G Baranov , Alex Krasnok , Andrea Alù

A concept of ultra-thin low frequency perfect sound absorber is proposed and demonstrated experimentally. To minimize non-linear effects, an high ratio of active area to total area is used to avoid large localized amplitudes. The absorber…

Classical Physics · Physics 2018-12-05 Yves Aurégan

The disappearance of the giant terahertz photoconductance of a quantum point contact under the increase in the photon energy, which was discovered experimentally (Otteneder et al., Phys. Rev. Applied 10 (2018) 014015) and studied by the…

Mesoscale and Nanoscale Physics · Physics 2022-08-08 D. M. Kazantsev , V. L. Alperovich , V. A. Tkachenko , Z. D. Kvon

Odd-even harmonics emitted from a laser-target system imprint rich, subtle information characterizing the system's dynamical asymmetry, which is desirable to decipher. In this Letter, we discover a simple universal relation between the…

Quantum Physics · Physics 2023-08-16 Doan-An Trieu , Ngoc-Loan Phan , Quan-Hao Truong , Hien T. Nguyen , Cam-Tu Le , DinhDuy Vu , Van-Hoang Le

We present a protocol based on the interplay between superradiance and superabsorption to achieve the coherent deflection of an atomic sample due to the momentum transfer from the atoms to a cavity field. The coherent character of this…

Quantum Physics · Physics 2025-09-19 L. F. Alves da Silva , L. M. R. Rocha , M. H. Y. Moussa

We study theoretically and numerically a new kind of spatial correlation for waves in disordered media. We define $C_{\Gamma}$ as the correlation function of the fluorescent decay rate of an emitter at two different positions inside the…

Optics · Physics 2017-08-02 Olivier Leseur , Romain Pierrat , Rémi Carminati

We have fabricated a centimeter-size single-layer graphene device, with a gate electrode, which can modulate the transmission of terahertz and infrared waves. Using time-domain terahertz spectroscopy and Fourier-transform infrared…

Dedicated optics with extremely short electron bunches enable synchrotron light sources to generate intense coherent THz radiation. The high degree of spatial compression in this so-called low-alpha optics entails a complex longitudinal…

Due to the experimental necessity we present a formula to determine the absorption strength by power losses inside a chaotic system (cavities, graphs, acoustic resonators, etc) when the antenna coupling, always present in experimental…

Mesoscale and Nanoscale Physics · Physics 2008-10-30 G. Baez , M. Martinez-Mares , R. A. Mendez-Sanchez

The vibrational density of states $D(\omega)$ of solids controls their thermal and transport properties. In crystals, the low-frequency modes are extended phonons distributed in frequency according to Debye's law, $D(\omega) \propto…

Soft Condensed Matter · Physics 2021-12-01 Shivam Mahajan , Massimo Pica Ciamarra
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