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Photomixing of two near-infrared lasers is well established for continuous-wave terahertz spectroscopy. Photomixing of three lasers allows us to measure at three terahertz frequencies simultaneously. Similar to Fourier spectroscopy, the…

Advances in the development of free-electron lasers offer the realistic prospect of high-resolution imaging to study the nanoworld on the time-scale of atomic motions. We identify X-ray Fourier Transform holography, (FTH) as a promising…

In coherent diffraction imaging (CDI) experiments, the intensity of the scattered wave impinging on an object is measured on an array of detectors. This signal can be interpreted as the square of the modulus of the Fourier transform of the…

Nonlinear interferometry with entangled photons allows for characterizing a sample without detecting the photons interacting with it. This method enables highly sensitive optical sensing in the wavelength regions where efficient detectors…

Optics · Physics 2025-08-11 Kazuki Hashimoto , Dmitri B. Horoshko , Maria V. Chekhova

Transform image processing methods are methods that work in domains of image transforms, such as Discrete Fourier, Discrete Cosine, Wavelet and alike. They are the basic tool in image compression, in image restoration, in image re-sampling…

Computer Vision and Pattern Recognition · Computer Science 2014-08-28 Leonid Yaroslavsky

We present an approach for improving spatial frequency sampling in active incoherent millimeter-wave (AIM) imaging systems using frequency diversity. AIM imaging relies on active transmission of spatio-temporally incoherent signals to…

Signal Processing · Electrical Eng. & Systems 2025-03-12 Jorge R. Colon-Berrios , Jeffrey A. Nanzer

Multispectral image fusion is a computer vision process that is essential to remote sensing. For applications such as dehazing and object detection, there is a need to offer solutions that can perform in real-time on any type of scene.…

Computer Vision and Pattern Recognition · Computer Science 2023-05-09 Nati Ofir , Jean-Christophe Nebel

We demonstrate single-pixel imaging in the spectral domain by encoding Fourier probe patterns onto the spectrum of a superluminescent laser diode using a programmable optical filter. As a proof-of-concept, we measure the…

Optics · Physics 2020-02-26 Piotr Ryczkowski , Caroline Amiot , John M. Dudley , Goery Genty

Complex-field imaging is indispensable for numerous applications at wavelengths from X-ray to THz, with amplitude describing transmittance (or reflectivity) and phase revealing intrinsic structure of the target object. Coherent diffraction…

Image and Video Processing · Electrical Eng. & Systems 2021-04-07 Meng Li , Liheng Bian , Guoan Zheng , Andrew Maiden , Yang Liu , Yiming Li , Qionghai Dai , Jun Zhang

It is shown here that precision is gained by analyzing the interferometric spectra directly from the interferograms, with no previous Fourier transformation to put them in the standard frequency domain. The method is based on the…

Instrumentation and Detectors · Physics 2018-04-20 Miguel Lagos , Rodrigo Paredes , Cesar Retamal

Achieving high spatial resolution is the goal of many imaging systems. Designing a high-resolution lens with diffraction-limited performance over a large field of view remains a difficult task in imaging system design. On the other hand,…

Feature extraction in noisy image datasets presents many challenges in model reliability. In this paper, we use the discrete Fourier transform in conjunction with persistent homology analysis to extract specific frequencies that correspond…

Computer Vision and Pattern Recognition · Computer Science 2025-12-09 Anil Chintapalli , Peter Tenholder , Henry Chen , Arjun Rao

Purpose: Long scan time in phase encoding for forming complete K-space matrices is a critical drawback of MRI, making patients uncomfortable and wasting important time for diagnosing emergent diseases. This paper aims to reducing the scan…

Computer Vision and Pattern Recognition · Computer Science 2022-03-14 Yiming Liu , Yanwei Pang , Ruiqi Jin , Zhenchang Wang

Dispersive Fourier transformation is a powerful technique in which spectral information is mapped into the time domain using chromatic dispersion. It replaces a spectrometer with an electronic digitizer, and enables real-time spectroscopy.…

Optics · Physics 2009-11-13 J. Chou , D. R. Solli , B. Jalali

Dispersive Fourier transformation is a powerful technique in which the spectrum of an optical pulse is mapped into a time-domain waveform using chromatic dispersion. It replaces a diffraction grating and detector array with a dispersive…

Optics · Physics 2009-11-13 Keisuke Goda , Kevin K. Tsia , Bahram Jalali

Terahertz waves hold immense potential across diverse fields, including healthcare monitoring, biomedical imaging, precision navigation, high-speed communication, security screening, industrial quality control, and space exploration.…

Optics · Physics 2026-04-13 Yifan Zhao , Shahed-E- Zumrat , Szu-An Tsao , Mona Jarrahi

Coherent diffraction imaging is a high-resolution imaging technique whose potential can be greatly enhanced by applying the extrapolation method presented here. We demonstrate enhancement in resolution of a non-periodical object…

Accelerator-based terahertz (THz) radiation has been expected to realize a high-power broadband source. Employing a low-emittance and short-bunch electron beam at a high repetition rate, a scheme of coherent diffraction-radiation in an…

A blind compressive sensing algorithm is proposed to reconstruct hyperspectral images from spectrally-compressed measurements.The wavelength-dependent data are coded and then superposed, mapping the three-dimensional hyperspectral datacube…

Computer Vision and Pattern Recognition · Computer Science 2015-10-28 Xin Yuan , Tsung-Han Tsai , Ruoyu Zhu , Patrick Llull , David Brady , Lawrence Carin

This paper reported a general noninterferometric high-accuracy quantitative phase imaging (QPI) method for arbitrary complex valued objects. Given by a typical 4f optical configuration as the imaging system, three frames of small-window…

Image and Video Processing · Electrical Eng. & Systems 2021-05-05 Jianhui Huang , An Pan , Huiliang Jin , Guoxiang Meng , Qian Ye
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