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We demonstrate a novel imaging approach and associated reconstruction algorithm for far-field coherent diffractive imaging, based on the measurement of a pair of laterally sheared diffraction patterns. The differential phase profile…

Optics · Physics 2018-05-23 G. S. M. Jansen , A. C. C. de Beurs , X. Liu , K. S. E. Eikema , S. Witte

Optical spectroscopic sensors are a powerful tool to reveal light-matter interactions in many fields, such as physics, biology, chemistry, and astronomy. Miniaturizing the currently bulky spectrometers has become imperative for the wide…

The technologically-relevant task of feature extraction from data performed in deep-learning systems is routinely accomplished as repeated fast Fourier transforms (FFT) electronically in prevalent domain-specific architectures such as in…

A simple and novel setup for high-frequency dielectric spectroscopy of materials has been developed using a portable vector network analyzer. The measurement principle is based on radio-frequency reflectometry, and both its capabilities and…

Instrumentation and Detectors · Physics 2024-02-02 Aitor Erkoreka , Josu Martinez-Perdiguero

We demonstrate a 13-fold speed improvement in broadband cantilever-enhanced photoacoustic spectroscopy (CEPAS) by combining it with phase-controlled Fourier-transform spectroscopy (PC-FTS) instead of traditional Fourier-transform infrared…

Optics · Physics 2022-12-21 Santeri Larnimaa , Mikhail Roiz , Markku Vainio

The time-domain technique for impedance spectroscopy consists of computing the excitation voltage and current response Fourier images by fast or discrete Fourier transformation and calculating their relation. Here we propose an alternative…

Data Analysis, Statistics and Probability · Physics 2017-12-14 Daniil D. Stupin , Sergei V. Koniakhin , Nikolay A. Verlov , Michael V. Dubina

In many processes, the variations in underlying characteristics can be approximated by noisy multi-periodic patterns. If large-scale patterns are superimposed by a noise with long-range correlations, the detection of multi-periodic patterns…

Quantitative Methods · Quantitative Biology 2019-12-09 V. R. Chechetkin , V. V. Lobzin

One of the key challenges in the area of signal processing on graphs is to design transforms and dictionaries methods to identify and exploit structure in signals on weighted graphs. In this paper, we first generalize graph Fourier…

Computer Vision and Pattern Recognition · Computer Science 2019-02-28 Jiasong Wu , Fuzhi Wu , Qihan Yang , Youyong Kong , Xilin Liu , Yan Zhang , Lotfi Senhadji , Huazhong Shu

This paper demonstrates the operation of a universal RF photonic circuit that consists of a generalized Mach Zehnder Interferometer architecture with its Nx1 combiner replaced by a NxN optical DFT network. The proposed circuit architecture…

Applied Physics · Physics 2022-02-15 Mehedi Hasan , Gazi Mahamud Hasan , Trevor Hall

We demonstrate a new computational illumination technique that achieves large space-bandwidth-time product, for quantitative phase imaging of unstained live samples in vitro. Microscope lenses can have either large field of view (FOV) or…

Optics · Physics 2015-10-16 Lei Tian , Ziji Liu , Li-Hao Yeh , Michael Chen , Jingshan Zhong , Laura Waller

Fourier ptychography (FP) is an enabling imaging technique that produces high-resolution complex-valued images with extended field coverages. However, when FP images a phase object with any specific spatial frequency, the captured images…

Spectral measurements in the infrared (IR) optical range provide unique fingerprints of materials which are useful for material analysis, environmental sensing, and health diagnostics. Current IR spectroscopy techniques require the use of…

Quantum Physics · Physics 2016-02-05 Dmitry A. Kalashnikov , Anna V. Paterova , Sergei P. Kulik , Leonid A. Krivitsky

We report a novel microscopy platform, termed Multi-Aperture Fourier ptychographic microscopy (MA-FPM), capable of realizing gigapixel complex field images with large data acquisition bandwidths - in gigapixels per second. MA-FPM is a…

Optics · Physics 2020-10-14 Pavan Chandra Konda , Jonathan M. Taylor , Andrew R. Harvey

A major limitation of transient optical spectroscopy is that relatively high laser fluences are required to enable broadband, multichannel detection with acceptable signal-to-noise levels. Under typical experimental conditions, many…

Optics · Physics 2023-05-03 Siedah J. Hall , Peter J. Budden , Anne Zats , Matthew Y. Sfeir

Digital Transforms have important applications on subjects such as channel coding, cryptography and digital signal processing. In this paper, two Fourier Transforms are considered, the discrete time Fourier transform (DTFT) and the finite…

Fourier ptychographic microscopy (FPM) is a recently developed imaging modality that uses angularly varying illumination to extend a system performance beyond the limit defined by its optical elements. The FPM technique applies a novel…

Optics · Physics 2014-05-02 Xiaoze Ou , Roarke Horstmeyer , Changhuei Yang , Guoan Zheng

In magnetic resonance imaging (MRI), the spectrometer is a fundamental component of MRI systems, responsible for the transmission of radiofrequency (RF) pulses that excite hydrogen nuclei and the subsequent acquisition of MR signals for…

Medical Physics · Physics 2024-09-16 Zesong Jiang , Muhang Zhang , Qing Zhang , Yuchong Xie

Coincidence technique and the coincidence measurement systems have been developed and applied for over 40 years. Most of popular coincidence measurement systems were based on analog electronics techniques such as time to amplitude…

Instrumentation and Detectors · Physics 2013-07-02 Pham Dinh Khang , Nguyen Xuan Hai , Nguyen Nhi Dien , Pham Ngoc Tuan , Dang Lanh , Nguyen Duc Hoa , Nguyen An Son

Many signals on Cartesian product graphs appear in the real world, such as digital images, sensor observation time series, and movie ratings on Netflix. These signals are "multi-dimensional" and have directional characteristics along each…

Methodology · Statistics 2017-12-22 Takashi Kurokawa , Taihei Oki , Hiromichi Nagao

The extraction of information carried by light plays an increasingly important role in optical communication, imaging, and detection. However, the information can only be successfully extracted when the light pulse is comparably strong,…

Optics · Physics 2026-05-25 Zhen Yang , Zeng-Quan Yan , Li Wang , Xiao-Wei Wang , Ka-Di Zhu , Xian-Min Jin
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