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Fourier transform spectroscopy (FTS) has been widely used in a variety of fields in research, industry, and medicine due to its high signal-to-noise ratio, simultaneous acquisition of signals in a broad spectrum, and versatility for…

We proposed a method to achieve superresolved optical imaging without beating the diffraction limit of light. This is achieved by magnifying the ideal optical image of the object through higher-order spatial frequency generation while…

Optics · Physics 2016-08-08 Zhixiang Li , Jianji Liu , Guoquan Zhang

We present experimental and numerical studies of localized terahertz surface waves on a subwavelength-thick metamaterial film consisting of in-plane split-ring resonators. A simple and intuitive model is derived that describes the…

Optics · Physics 2010-10-06 Benjamin Reinhard , Oliver Paul , Rene Beigang , Marco Rahm

We propose a scheme for imaging periodic surfaces using a superlens. By employing an inverse scattering model and the transformed field expansion method, we derive an approximate reconstruction formula for the surface profile, assuming…

Numerical Analysis · Mathematics 2024-03-05 Peijun Li , Yuliang Wang

We investigate the spatially and temporally resolved four-wave mixing of terahertz fields and optical pulses in large band-gap dielectrics, such as diamond. We show that it is possible to perform beam profiling and space-time resolved…

We demonstrate a single-shot terahertz spectrometer consisting of a modified Mach-Zehnder interferometer and a microbolometer focal plane array. The spectrometer is simple to use and can measure terahertz field autocorrelations and spectral…

Instrumentation and Detectors · Physics 2020-06-08 Dogeun Jang , Hanran Jin , Ki-Yong Kim

One of the solutions of depth imaging of moving scene is to project a static pattern on the object and use just a single image for reconstruction. However, if the motion of the object is too fast with respect to the exposure time of the…

Computer Vision and Pattern Recognition · Computer Science 2017-10-03 Yuki Shiba , Satoshi Ono , Ryo Furukawa , Shinsaku Hiura , Hiroshi Kawasaki

Lenses that can collect the perfect image of an object must restore propagative and evanescent waves. However, for efficient information transfer, e.g., in compressed sensing, it is often desirable to detect only the fast spatial variations…

Optics · Physics 2016-02-01 Miguel Molerón , Chiara Daraio

Ultrafast single-shot imaging techniques now reach frame rates of tens of tera-frame-per-second (Tfps) and long sequence depths but are often too complex for large-scale use, both in terms of image acquisition and reconstruction. We propose…

Presented is a novel way to combine snapshot compressive imaging and lateral shearing interferometry in order to capture the spatio-spectral phase of an ultrashort laser pulse in a single shot. A deep unrolling algorithm is utilised for the…

Second harmonic generation microscopy (SHG) is a powerful imaging modality which has found applications in investigating both biological and synthetic nanostructures. Like all optical microscopy techniques, the resolution of SHG is limited…

Visualizing information inside objects is an ever-lasting need to bridge the world from physics, chemistry, biology to computation. Among all tomographic techniques, terahertz (THz) computational imaging has demonstrated its unique sensing…

Image and Video Processing · Electrical Eng. & Systems 2022-05-03 Weng-Tai Su , Yi-Chun Hung , Po-Jen Yu , Chia-Wen Lin , Shang-Hua Yang

We present a development of a high precision, tunable far-infrared (terahertz) frequency-domain dielectric spectrometer for studying the dynamics of biomolecules in aqueous solutions in the gigahertz-to-terahertz frequency. As a first…

Biological Physics · Physics 2016-01-20 Deepu K. George , Ali Charkhesht , N. Q. Vinh

This paper presents a deep learning approach for image retrieval and pattern spotting in digital collections of historical documents. First, a region proposal algorithm detects object candidates in the document page images. Next, deep…

Computer Vision and Pattern Recognition · Computer Science 2022-08-05 Caio da S. Dias , Alceu de S. Britto , Jean P. Barddal , Laurent Heutte , Alessandro L. Koerich

We propose a methodology that exploits large and diverse data sets to accurately estimate the ambient medium's Green's functions in strongly scattering media. Given these estimates, obtained with and without the use of neural networks,…

Machine Learning · Computer Science 2024-12-05 Alexander Christie , Matan Leibovich , Miguel Moscoso , Alexei Novikov , George Papanicolaou , Chrysoula Tsogka

Single-shot terahertz (THz) spectroscopy probes sub-picosecond, non-repetitive events by combining the advantages of laser absorption techniques with the phase-sensitive detection of interferometric methods. However, its usage as a…

Optics · Physics 2025-01-07 Charan R. Nallapareddy , Thomas C. Underwood

Hyperspectral microscopy is an imaging technique that provides spectroscopic information with high spatial resolution. When applied in the relevant wavelength region, such as in the infrared (IR), it can reveal a rich spectral fingerprint…

The goal of synthetic aperture imaging is to estimate the reflectivity of a remote region of interest by processing data gathered with a moving sensor which emits periodically a signal and records the backscattered wave. We introduce and…

Image and Video Processing · Electrical Eng. & Systems 2019-07-05 Liliana Borcea , Josselin Garnier

In this paper, we propose a novel approach to hyperspectral image super-resolution by modeling the global spatial-and-spectral correlation and local smoothness properties over hyperspectral images. Specifically, we utilize the tensor…

Computer Vision and Pattern Recognition · Computer Science 2016-01-26 Shiying He , Haiwei Zhou , Yao Wang , Wenfei Cao , Zhi Han

Terahertz spectrometers with a wide instantaneous frequency coverage for passive remote sensing are enormously attractive for many terahertz applications, such as astronomy, atmospheric science and security. Here we demonstrate a wide-band…