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Related papers: Coherent Perfect Absorbers: Time-reversed Lasers

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Absorption of microwave by metallic conductors is exclusively inefficient, though being natively broadband, due to the huge impedance mismatch between metal and free space. Reducing the thickness to ultrathin conductive film may improve the…

A metamaterial perfect absorber consisting of a tri-layer (Al/ZnS/Al) metal-dielectric-metal system with top aluminium nano-disks is fabricated by laser-interference lithography and lift-off processing. The metamaterial absorber had peak…

Optics · Physics 2018-11-02 Sriram Guddala , Raghwendra Kumar , S. Anantha Ramakrishna

The simultaneous existence of coherent perfect absorption (CPA) and lasing is one of the most intriguing features of non-Hermitian photonics. However, the link between CPA lasing and PT symmetry breaking at the exceptional point (EP) needs…

Optics · Physics 2019-08-14 Denis Novitsky

We propose a new method to measure the absolute photon absorption cross section of neutral molecules in a molecular beam. It is independent of our knowledge of the particle beam density, nor does it rely on photo-induced fragmentation or…

Quantum Physics · Physics 2008-12-31 Stefan Nimmrichter , Klaus Hornberger , Hendrik Ulbricht , Markus Arndt

Coherent LiDAR (Light Detecting And Ranging) is a promising 3D imaging technology that provides significant advantages over more traditional LiDAR systems. In addition to being immune to ambient light, it directly measures the velocity of…

Applied Physics · Physics 2022-01-25 Alexander Y. Piggott

When two identical (coherent) beams are injected at a semi-infinite non-Hermitian medium from left and right, we show that both reflection $(r_L,r_R)$ and transmission $(t_L,t_R)$ amplitudes are non-reciprocal. In a parametric domain, there…

Quantum Physics · Physics 2018-02-21 Zafar Ahmed , Dona Ghosh , Sachin Kumar

The capability of optical resonators to extend the effective radiation-matter interaction length originates from a multipass effect, hence is intrinsically limited by the resonator quality factor. Here, we show that this constraint can be…

Optics · Physics 2016-07-05 P. Malara , C. E. Campanella , A. Giorgini , S. Avino , P. De Natale , G. Gagliardi

Temporal coherence is a fundamental property of macroscopic quantum systems, such as lasers in optics and Bose-Einstein condensates in atomic gases and it is a crucial issue for interferometry applications with light or matter waves.…

Quantum Gases · Physics 2015-05-13 Alice Sinatra , Yvan Castin , Emilia Witkowska

The basic understanding of high-intensity femtosecond laser absorption in a solid is crucial for high-energy-density science. This multidimensional problem has many variables like laser parameters, solid target material, and geometry of the…

We study the optimal diffusive transmission and absorption of broadband or polychromatic light in a disordered medium. By introducing matrices describing broadband transmission and reflection, we formulate an extremal eigenvalue problem…

Optics · Physics 2015-11-26 Chia Wei Hsu , Arthur Goetschy , Yaron Bromberg , A. Douglas Stone , Hui Cao

Holographic coherent X-ray imaging enables nanoscale imaging of biological cells and tissues, rendering both phase and absorption contrast, i.e. real and imaginary parts of the refractive index. Unlike the standard model, which assumes a…

Analysis of PDEs · Mathematics 2026-05-29 Thorsten Hohage , Milad Karimi , Björn Müller

Recent advances in the field of attosecond science hold the promise of tracking electronic processes at the shortest space and time scales. Imaging methods that combine attosecond temporal with nanometer spatial resolution are currently out…

The lasing and coherent perfect absorption (CPA) properties of $\mathcal{PT}$-symmetric microrings with mixed index and gain gratings, externally coupled to a bus waveguide, are theoretically investigated. For a complex grating at the…

Optics · Physics 2015-06-22 Stefano Longhi , Liang Feng

Coherent Diffractive Imaging is a lensless technique that allows imaging of matter at a spatial resolution not limited by lens aberrations. This technique exploits the measured diffraction pattern of a coherent beam scattered by periodic…

Computational Physics · Physics 2025-08-27 Alessandro Colombo , Davide Emilio Galli , Liberato De Caro , Francesco Scattarella , Elvio Carlino

Experimental evidence of an absorbing phase transition, so far associated with spatio-temporal dynamics is provided in a purely temporal optical system. A bistable semiconductor laser, with long-delayed opto-electronic feedback and…

Statistical Mechanics · Physics 2018-05-02 Marco Faggian , Francesco Ginelli , Francesco Marino , Giovanni Giacomelli

Optical low-coherence reflectometry is capable of unambiguously measuring positions of stacked, partially reflective layers in a sample object. It relies on the low coherence of the light source and the absolute distances are obtained from…

Quantum Physics · Physics 2020-04-07 Manuel Unternährer , André Stefanov

Polarization- and wavelength-sensitive absorbers for homogeneous electromagnetic waves are crucial in photovoltaics, imaging and telecommunications. Here, we report on an absorber selective to the topological structure of light. An…

Optics · Physics 2025-09-16 Luka Vignjevic , Eric Plum , Nikitas Papasimakis , Nikolay I Zheludev

Poorly transparent barriers (e.g., reinforced walls, shielding panels, metallic or high-contrast dielectrics) strongly reflect incident radiation, limiting wireless power transfer (WPT) unless the barrier is structurally modified to support…

Optics · Physics 2025-12-25 Alex Krasnok

A recursive scheme for the design of scatterers acting simultaneously as emitters and absorbers, such as lasers and coherent perfect absorbers in optics, at multiple prescribed frequencies is proposed. The approach is based on the assembly…

Emission and absorption of light lie at the heart of light-matter interaction. Although emission and absorption rates are regarded as intrinsic properties of atoms and molecules, various ways to modify these rates have been sought in…

Quantum Physics · Physics 2023-02-27 Daeho Yang , Seung-hoon Oh , Junseok Han , Gibeom Son , Jinuk Kim , Junki Kim , Moonjoo Lee , Kyungwon An
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