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Related papers: Wide-open, high-resolution microwave/millimeter-wa…

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We present a Faraday rotation spectroscopy (FRS) technique for measurements on the micron scale. Spectral acquisition speeds of many orders of magnitude faster than state-of-the-art modulation spectroscopy setups are demonstrated. The…

Context: Ground-based telescopes are susceptible to seeing, an atmospheric phenomenon that reduces the resolving power of large observatories to that of a home telescope. Compensating these effects is therefore critical to realizing the…

Instrumentation and Methods for Astrophysics · Physics 2025-11-11 Jacob Trzaska , Amit Ashok

We have designed and constructed a ``dispersed Fourier Transform Spectrometer'' (dFTS), consisting of a conventional FTS followed by a grating spectrometer. By combining these two devices, we negate a substantial fraction of the sensitivity…

We demonstrate high-resolution photonic RF filters using an RF bandwidth scaling approach based on integrated Kerr optical micro-combs. By employing both an active nonlinear micro-ring resonator (MRR) as a high-quality micro-comb source and…

Continuous wavefront sensing benefits space observatories in on-orbit optical performance maintenance. To measure the phase of a wavefront, phase retrieval is an attractive technique as it uses multiple point spread function (PSF) images…

Instrumentation and Methods for Astrophysics · Physics 2024-09-17 Hyukmo Kang , Kyle Van Gorkom , Meghdoot Biswas , Daewook Kim , Ewan S. Douglas

Open dielectric resonators of different shapes are widely used for the manufacture of microlasers. A precise determination of their resonance frequencies and widths is crucial for their design. Most microlasers have a flat cylindrical…

Optics · Physics 2009-08-31 S. Bittner , B. Dietz , M. Miski-Oglu , P. Oria Iriarte , A. Richter , F. Schäfer

A proposal for fast-switching broadband frequency-shifting technology making use of frequency conversion in a nonlinear crystal is set forth, whereby the shifting is imparted to the converted photons by creating a bank of…

For efficient spectroscopic redshift identification of early galaxies in the northern hemisphere, we aim to combine the Large Millimeter Telescope (LMT) with a wide-band heterodyne receiver, FINER, which will cover radio frequencies of…

The wavefront measurement of a light beam is a complex task, which often requires a series of spatially resolved intensity measurements. For instance, a detector array may be used to measure the local phase gradient in the transverse plane…

An experimental realization of high-precision direct frequency comb spectroscopy using counter-propagating femtosecond pulses on two-photon atomic transitions is presented. Doppler broadened background signal, hampering precision…

Atomic Physics · Physics 2013-07-11 Itan Barmes , Stefan Witte , Kjeld S. E. Eikema

Diffusing Wave Spectroscopy (DWS) is an extension of standard dynamic light scattering (DLS), applied to soft materials that are turbid or opaque. The propagation of light is modeled using light diffusion, characterized by a light diffusion…

Soft Condensed Matter · Physics 2025-12-15 Manuel Helfer , Chi Zhang , Frank Scheffold

Multiple-input multiple-output (MIMO) radar offers several performance and flexibility advantages over traditional radar arrays. However, high angular and Doppler resolutions necessitate a large number of antenna elements and the…

Signal Processing · Electrical Eng. & Systems 2025-09-11 Chandrashekhar Rai , Himali Singh , Arpan Chattopadhyay

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

In radar systems, high resolution in the Doppler dimension is important for detecting slow-moving targets as it allows for more distinct separation between these targets and clutter, or stationary objects. However, achieving sufficient…

Computer Vision and Pattern Recognition · Computer Science 2025-05-26 Denisa Qosja , Kilian Barth , Simon Wagner

The resolution limits of classical spectroscopy can be surpassed by quantum-inspired methods leveraging the information contained in the phase of the complex electromagnetic field. Their counterpart in spatial imaging has been widely…

Optics · Physics 2024-09-02 Michał Lipka , Michał Parniak

Here we demonstrate an on-chip electro-optic frequency shifter that is precisely controlled using only a single-tone microwave signal. This is accomplished by engineering the density of states of, and coupling between, optical modes in…

Orthogonal time frequency space (OTFS) modulation was proposed to tackle the destructive Doppler effects in wireless communications, with potential applications to many other areas. In this paper, we investigate its application to radar…

Information Theory · Computer Science 2019-01-29 P. Raviteja , Khoa T. Phan , Yi Hong , Emanuele Viterbo

In this paper, the authors propose a two-dimensional, wide dynamic range, linear displacement sensor using microwave methods. The microwave sensor circuit employs a cylindrical dielectric resonator proximity coupled to a pair of orthogonal…

Applied Physics · Physics 2023-02-28 Premsai Regalla , A. V. Praveen Kumar

The emergence of far-field super-resolution microscopy has rejuvenated the possibility for nanoscale imaging. Approaches to far-field super-resolution that utilize point scanning often depends on spatially reducing the size of the focused…

Optics · Physics 2022-06-17 Ning Xu , Guoxuan Liu , Qiaofeng Tan

In this paper, we propose and evaluate two novel double-sequence low-resolution frequency synchronization methods in millimeter-wave (mmWave) systems. In our system model, the base station uses analog beams to send the synchronization…

Signal Processing · Electrical Eng. & Systems 2018-12-11 Dalin Zhu , Ralf Bendlin , Salam Akoum , Arunabha Ghosh , Robert W. Heath