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Refraction at a smooth interface is accompanied by momentum transfer normal to the interface. We show that corrugating an initially smooth, totally reflecting, non-metallic interface provides a momentum kick parallel to the surface, which…

Other Condensed Matter · Physics 2009-11-13 W. T. Lu , Y. J. Huang , P. Vodo , R. K. Banyal , C. H. Perry , S. Sridhar

We present an implementation of the single-pixel imaging approach into a terahertz (THz) time-domain spectroscopy (TDS) system. We demonstrate the indirect coherent reconstruction of THz temporal waveforms at each spatial position of an…

Image and Video Processing · Electrical Eng. & Systems 2020-02-19 Luca Zanotto , Riccardo Piccoli , Junliang Dong , Diego Caraffini , Roberto Morandotti , Luca Razzari

An experimental evidence of subwavelength imaging with a "lens", which is a uniaxial negative permittivity wire medium slab, is reported. The slab is formed by gratings of long thin parallel conducting cylinders. Taking into account the…

We study the diffraction produced by a $PT$-symmetric volume Bragg grating that combines modulation of refractive index and gain/loss of the same periodicity with a quarter-period shift between them. Such a complex grating has a directional…

Optics · Physics 2014-12-02 Mykola Kulishov , H. F. Jones , Bernard Kress

Conventional surface-relief gratings are inefficient at deflecting normally-incident light by large angles. This constrains their use in many applications and limits the overall efficiency of any optical instrument integrating gratings.…

Optics · Physics 2021-11-19 Ashutosh Patri , Stephane Kena-Cohen , Christophe Caloz

Coherent diffractive imaging is unique as the only route for achieving diffraction-limited spatial resolution in the extreme ultraviolet and X-ray regions, limited only by the wavelength of the light. Recently, advances in coherent short…

Time-of-flight (ToF) devices have greatly propelled the advancement of various multi-modal perception applications. However, achieving accurate rendering of time-resolved information remains a challenge, particularly in scenes involving…

Graphics · Computer Science 2024-06-17 Qianyue He , Dongyu Du , Haitian Jiang , Xin Jin

This paper introduces temporal Bragg gratings as a new class of broadband, reconfigurable parametric amplifiers. We present a comprehensive investigation of power amplification in temporal Bragg gratings, spatially periodic structures with…

Optics · Physics 2026-04-15 Sajjad Taravati

In this paper, we propose a method for tailoring the absorption in a photonic crystal membrane. For that purpose, we first applied Time Domain Coupled Mode Theory to such a subwavelength membrane and demonstrated that 100% resonant…

This paper is concerned with the inverse time-harmonic elastic scattering problem of recovering unbounded rough surfaces in two dimensions. We assume that elastic plane waves with different directions are incident onto a rigid rough surface…

Numerical Analysis · Mathematics 2018-04-09 Guanghui Hu , Xiaoli Liu , Bo Zhang , Haiwen Zhang

Time-varying metamaterials are artificial materials whose electromagnetic properties change over time. Similar to a spatial medium discontinuity, a sudden change in time of the metamaterial refractive index induces the generation of a…

Classical Physics · Physics 2025-02-06 Davide Ramaccia , Alessandro Toscano , Filiberto Bilotti

Spatial sampling is traditionally studied in a static setting where static sensors scattered around space take measurements of the spatial field at their locations. In this paper we study the emerging paradigm of sampling and reconstructing…

Multimedia · Computer Science 2015-06-12 Jayakrishnan Unnikrishnan , Martin Vetterli

A simple method of phase-and-amplitude extraction is derived that corrects for image blurring induced by partially spatially coherent incident illumination using only a single intensity image as input. The method is based on Fresnel…

Optics · Physics 2019-11-19 Mario A. Beltran , David M. Paganin , Daniele Pelliccia

This paper presents an innovative approach to computational acoustic imaging of biperiodic surfaces, exploiting the capabilities of an acoustic superlens to overcome the diffraction limit. We address the challenge of imaging physical…

Analysis of PDEs · Mathematics 2026-01-05 Yuliang Wang

Accurate measurement of the pulse duration of ultrashort, ultra-intense laser pulses at focus is essential for strong-field science. Most existing diagnostics, however, cannot allow direct in situ measurement in the focal region because of…

We introduce the concept of coherent temporal imaging and its combination with the anamorphic stretch transform. The new system can measure both temporal profile of fast waveforms as well as their spectrum in real time and at…

Optics · Physics 2013-11-05 Mohammad H. Asghari , Bahram Jalali

Image matting refers to the estimation of the opacity of foreground objects. It requires correct contours and fine details of foreground objects for the matting results. To better accomplish human image matting tasks, we propose the Cascade…

Computer Vision and Pattern Recognition · Computer Science 2021-05-11 Zijian Yu , Xuhui Li , Huijuan Huang , Wen Zheng , Li Chen

This study formally adapts the time-domain linear sampling method (TLSM) for ultrasonic imaging of stationary and evolving fractures in safety-critical components. The TLSM indicator is then applied to the laboratory test data of [22, 18]…

Numerical Analysis · Mathematics 2022-09-16 Xiaoli Liu , Jian Song , Fatemeh Pourahmadian , Houssem Haddar

Since its first demonstration in 1995, terahertz time-domain imaging has attracted an increasingly growing interest for its ability to reveal spectral fingerprints of materials, probe changes in refractive index and absorption, as well as…

Mid-infrared photothermal microscopy is a highly promising imaging technique that enables spatially resolved vibrational fingerprinting. The combination of infrared induced heating with optical readout at visible wavelengths provides…

Optics · Physics 2025-08-05 Dennis van de Lockand , Daan Wolters , Matz Liebel
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