Related papers: Coherent Perfect Absorbers: Time-reversed Lasers
Coherent Perfect Absorber (CPA) and Laser is a pair of inversely worked wave structure satisfying the time-reversal relation. We point out that, if the wave energy absorbed by CPA can be recovered by somewhat way and then be reemitted by…
We identify a family of unusual slow-light modes occurring in lossy multi-mode grating waveguides, for which either the forward or backward mode components, or both, become degenerate. In the fully-degenerate case, by varying the wave…
High-order perfect absorption of coherent input has recently attracted significant attention due to its broadband absorption capacity. However, the realization of a high-order perfect absorber relies on the exceptional point (EP) to…
Based on both analytical dipole model analyses and numerical simulations, we propose a concept of coherent perfect nanoabsorbers (CPNAs) for divergent beams. This concept makes use of the properties of a slab with negative refraction and…
Time-invariant photonic structures amplify or absorb light based on their intrinsic material gain or loss. The coherent interference of multiple beams in space, e.g., in a resonator, can be exploited to tailor the wave interaction with…
Here we propose a route to the high-Q perfect absorption of light by introducing the concept of a Fano anti-laser. Based on the drastic spectral variation of the optical phase in a Fano-resonant system, a spectral singularity for…
The CPA-laser is a coexisting state of coherent perfect absorption and lasing that was proposed in parity-time ($\cal PT$) symmetric photonic systems. In this work we show that the spectral signature of a CPA-laser displayed by the singular…
We prove that coherent perfect absorption (CPA) without lasing is {\bf not} possible in the PT-symmetric domain as the s-matrix is such that $|\det S(\pm k)|=1$. We study coherent scattering from three complex potentials, one solved…
We present an algorithm for coherent diffractive imaging with phaseless measurements. It treats the forward model as a combination of coherent and incoherent waves. The algorithm reconstructs absorption and phase contrast that quantifies…
Absorption imaging is a commonly adopted method to acquire, with high temporal resolution, spatial information on a partially transparent object. It relies on the interference between a probe beam and the coherent response of the object. In…
An optical spectral singularity is a zero-width resonance that corresponds to lasing at threshold gain. Its time-reversal causes coherent perfect absorption of light and forms the theoretical basis of antilasing. In this article we explore…
Coherent perfect absorption (CPA) was introduced as a classical optics phenomenon of a standing-wave absorption by a subwavelength film. In this paper, we develop a theory of CPA of quantized standing waves taking account of a subwavelength…
We measure the absolute absorption cross section of molecules using a matter-wave interferometer. A nanostructured density distribution is imprinted onto a dilute molecular beam through quantum interference. As the beam crosses the light…
Recently, a broad spectrum of exceptional scattering effects, including bound states in the continuum, exceptional points in PT-symmetrical non-Hermitian systems, and many others attainable in wisely suitably engineered structures have been…
Through temporal shaping of the excitation signal, the complex-frequency scattering zeros of a lossless structure can be accessed, enabling a storage-release mechanism referred to as coherent virtual absorption. Practical demonstrations of…
We identify a new kind of physically realizable exceptional point (EP) corresponding to degenerate coherent perfect absorption, in which two purely incoming solutions of the wave operator for electromagnetic or acoustic waves coalesce to a…
We investigate a unique type of zero-index medium with both gain and loss (ZIMGL), whose effective permittivity and permeability are purely imaginary and of opposite signs. We show analytically that, by using a slab of ZIM-GL with equal…
To effectively apply passive speckle reduction methods, it is essential to use an illumination system that maximally exploits the non-ideal temporal coherence and angular diversity (spatial coherence reduction) of laser light. This study…
Coherent perfect absorption (CPA) is an interference process associated with the zeros of the scattering matrix that enables light-with-light interactions in linear systems, of interest for optical computing, data processing and sensing.…
Generically, a laser is composed of an optical resonator coupled to a gain medium. If the light amplification via stimulated emission dominates the mirror losses, the emitted light is coherent. Recent studies have shown that sub-wavelength…