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We present a novel frequency-filtering method for measuring and calculating frequency-filtered photon-correlations. This novel method is a cavity-based system we call the multi-mode array filter, which consists of an array of tunable…

Quantum Physics · Physics 2024-08-20 Jacob Ngaha , Scott Parkins , Howard J. Carmichael

Sub-sampling can acquire directly a passband within a broad radio frequency (RF) range, avoiding down-conversion and low-phase-noise tunable local oscillation (LO). However, sub-sampling suffers from band folding and self-image…

Instrumentation and Detectors · Physics 2017-07-29 Wenhui Hao , Yitang Dai , Feifei Yin , Yue Zhou , Jianqiang Li , Jian Dai , Wangzhe Li , Kun Xu

Recent progress in image deblurring techniques focuses mainly on operating in both frequency and spatial domains using the Fourier transform (FT) properties. However, their performance is limited due to the dependency of FT on stationary…

Computer Vision and Pattern Recognition · Computer Science 2024-09-04 Subhajit Paul , Sahil Kumawat , Ashutosh Gupta , Deepak Mishra

We present a rapid-scanning approach to fluorescence-detected two-dimensional electronic spectroscopy that combines acousto-optic phase-modulation with digital lock-in detection. The approach shifts the signal detection window to suppress…

Time of flight cameras may emerge as the 3-D sensor of choice. Today, time of flight sensors use phase-based sampling, where the phase delay between emitted and received, high-frequency signals encodes distance. In this paper, we present a…

Computer Vision and Pattern Recognition · Computer Science 2015-03-11 Achuta Kadambi , Vage Taamazyan , Suren Jayasuriya , Ramesh Raskar

The Fast Fourier Transform (FFT) is a numerical operation that transforms a function into a form comprised of its constituent frequencies and is an integral part of scientific computation and data analysis. The objective of our work is to…

Distributed, Parallel, and Cluster Computing · Computer Science 2025-02-04 Sudhanshu Kulkarni , Burlen Loring , E. Wes Bethel

Optical turbulence modelling and simulation are crucial for developing astronomical ground-based instruments, laser communication, laser metrology, or any application where light propagates through a turbulent medium. In the context of…

Instrumentation and Methods for Astrophysics · Physics 2024-04-05 A. Berdja , M. Hadjara , M. Carbillet , R. L. Bernardi , R. G. Petrov

Fourier-transform infrared spectroscopy (FTIR) is the golden standard of mid-infrared (MIR) molecular spectroscopic analysis through optically-encoded vibrational signatures. Michelson-type FTIR and MIR dual-comb spectrometers allow us to…

Optics · Physics 2025-05-06 Kazuki Hashimoto , Venkata Ramaiah Badarla , Takuro Ideguchi

Band-resolved frequency modulation spectroscopy is a common method to measure weak signals of radiative ensembles. When the optical depth of the medium is large, the signal drops exponentially and the technique becomes ineffective. In this…

We have developed an imaging Fourier transform spectrometer (FTS) for space-based far-infrared astronomical observations. The FTS employs a newly developed photoconductive detector arrays with a capacitive trans-impedance amplifier, which…

The modulation transfer function (MTF) is widely used to characterise the performance of optical systems. Measuring it is costly and it is thus rarely available for a given lens specimen. Instead, MTFs based on simulations or, at best, MTFs…

Computer Vision and Pattern Recognition · Computer Science 2018-05-07 Matthias Bauer , Valentin Volchkov , Michael Hirsch , Bernhard Schölkopf

The knowledge of the exact structure of the optical system PSF enables a high-quality image reconstruction in fluorescence microscopy. Accurate PSF models account for the vector nature of light and the phase and amplitude modifications.…

Optical spectrum analysis is the cornerstone of spectroscopic sensing, optical network performance monitoring, and hyperspectral imaging. While conventional high-performance spectrometers used to perform such analysis are often large…

Applied Physics · Physics 2018-03-19 Derek M. Kita , Brando Miranda , David Favela , David Bono , Jerome Michon , Hongtao Lin , Tian Gu , Juejun Hu

We propose a new Fourier-transform spectroscopy technique based on the rotational Doppler effect. The technique offers an application for optical vortex frequency combs, where each frequency component carries a unique amount of orbital…

Optics · Physics 2024-10-28 Santeri Larnimaa , Markku Vainio

This paper presents an adaptive waveform design method using Multi-Tone Sinusoidal Frequency Modulation (MTSFM). The MTSFM waveform's modulation function is represented as a finite Fourier series expansion. The Fourier coefficients are…

Signal Processing · Electrical Eng. & Systems 2021-05-04 David A. Hague

A simplified Doppler frequency shift measurement approach based on Serrodyne optical frequency translation is reported. A sawtooth wave with an appropriate amplitude is sent to one phase modulation arm of a Mach-Zehnder modulator in…

Instrumentation and Detectors · Physics 2021-08-25 Yang Chen , Taixia Shi

We demonstrate a new simple technique to measure IR frequencies near 30 THz using a femtosecond (fs) laser optical comb and sum-frequency generation. The optical frequency is directly compared to the distance between two modes of the fs…

A multichannel dual-comb spectroscopy (DCS) approach for high-resolution, broadband spectral measurements is presented, demonstrating its effectiveness in studying complex atomic systems. By implementing a photodetector array, we enhance…

Atomic Physics · Physics 2025-03-14 R. Aramyan , O. Tretiak , S. S. Sahoo , D. Budker

The paper considers an inverse problem of reconstructing the spatially distributed complex dielectric permittivity function using backscattered data of the electric field in the frequency domain. We develop iterative algorithm for…

Medical Physics · Physics 2024-10-29 Larisa Beilina , Anders Eriksson , Noora Neittaanmäki

Faraday tomography is a new method of the study of cosmic magnetic fields enabled by broadband low-frequency radio observations. By Faraday tomography, it is possible to obtain the Faraday dispersion function which contains information on…

Astrophysics of Galaxies · Physics 2023-03-15 Keitaro Takahashi