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We study optical spectra of finite electronic quantum systems at frequencies smaller than the plasma frequency using a quasi-classical approach. This approach includes collective effects and enables us to analyze how the nature of the…

Mesoscale and Nanoscale Physics · Physics 2009-10-31 M. Santer , B. Mehlig

We demonstrate broadband and sensitive cavity ring-down spectroscopy using a near infrared frequency comb and a time-resolved Fourier transform spectrometer. The cavity decays are measured simultaneously and spectrally sorted, leading to…

Optics · Physics 2022-01-28 Romain Dubreoucq , Lucile Rutkowski

We present two versatile methods to generally enhance self-supervised monocular depth estimation (MDE) models. The high generalizability of our methods is achieved by solving the fundamental and ubiquitous problems in photometric loss…

Computer Vision and Pattern Recognition · Computer Science 2022-10-17 Xingyu Chen , Thomas H. Li , Ruonan Zhang , Ge Li

Differential wavefront sensing is an essential technique for optimising the performance of many precision interferometric experiments. Perhaps the most extensive application of this is for alignment sensing using radio-frequency beats…

Instrumentation and Detectors · Physics 2021-05-26 Daniel D. Brown , Huy Tuong Cao , Alexei Ciobanu , Peter Veitch , David Ottaway

A general-purpose all-fiber spectrometer is demonstrated to overcome the trade-off between spectral resolution and bandwidth. By integrating a wavelength division multiplexer with five multimode optical fibers, we have achieved 100 nm…

Instrumentation and Detectors · Physics 2016-08-26 Seng Fatt Liew , Brandon Redding , Michael A. Choma , Hemant D. Tagare , Hui Cao

Frequency comb assisted diode laser spectroscopy, employing both the accuracy of an optical frequency comb and the broad wavelength tuning range of a tunable diode laser, has been widely used in many applications. In this letter we present…

Optical phase-spaces represent fields of any spatial coherence, and are typically measured through phase-retrieval methods involving a computational inversion, interference, or a resolution-limiting lenslet array. Recently, a weak-values…

Optics · Physics 2018-09-12 Samuel H. Knarr , Daniel J. Lum , James Schneeloch , John C. Howell

In this paper, a novel method to enhance Frequency Modulated Continuous Wave (FMCW) THz imaging resolution beyond its diffraction limit is proposed. Our method comprises two stages. Firstly, we reconstruct the signal in depth-direction…

Image and Video Processing · Electrical Eng. & Systems 2019-07-03 Tak Ming Wong , Matthias Kahl , Peter Haring Bolívar , Andreas Kolb

Precision spectroscopy of solid-state systems is challenging due to inhomogeneous broadening. We describe a technique -- coherent quantum beats -- that enables the measurement of small frequency shifts within an inhomogeneously broadened…

Atomic Physics · Physics 2023-07-04 Harish D. Ramachandran , Julia E. Ford , Amar C. Vutha

We show that radio-frequency spectroscopy on weakly-bound molecules is a powerful and sensitive tool to probe molecular energy structure as well as atomic scattering properties. An analytic expression of the rf excitation lineshape is…

Superconductivity · Physics 2007-05-23 Cheng Chin , Paul S. Julienne

Frequency-bin qudits constitute a promising tool for quantum information processing, but their high dimensionality can make for tedious characterization measurements. Here we introduce and compare compressive sensing and Bayesian mean…

We investigate the problem of reconstructing signals from a subsampled convolution of their modulated versions and a known filter. The problem is studied as applies to specific imaging systems relying on spatial phase modulation by randomly…

Information Theory · Computer Science 2016-03-23 Sohail Bahmani , Justin Romberg

We demonstrate that conventional modulated spectroscopy apparatus, used for laser frequency stabilization in many atomic physics laboratories, can be enhanced to provide a wideband lock delivering deep suppression of frequency noise across…

Atomic Physics · Physics 2013-02-20 Vlad Negnevitsky , Lincoln D. Turner

We investigate theoretically dark resonance spectroscopy for a dilute atomic vapor confined in a thin (micro-metric) cell. We identify the physical parameters characterizing the spectra and study their influence. We focus on a Hanle-type…

Quantum Physics · Physics 2009-11-13 Horacio Failache , Lorenzo Lenci , Arturo Lezama , Daniel Bloch , Martial Ducloy

Bandpass signals are an important sub-class of bandlimited signals that naturally arise in a number of application areas but their high-frequency content poses an acquisition challenge. Consequently, "Bandpass Sampling Theory" has been…

Information Theory · Computer Science 2023-07-12 Gal Shtendel , Dorian Florescu , Ayush Bhandari

A theoretical model of the influence of detection bandwidth properties on observed line shapes in laser absorption spectroscopy is described. The model predicts artificial frequency shifts, extra broadenings and line asymmetries which must…

Light beams carrying orbital angular momentum are key resources in modern photonics. In many applications, the ability of measuring the complex spectrum of structured light beams in terms of these fundamental modes is crucial. Here we…

Longitudinal collective modes of a bunched beam with a repulsive inductive impedance (the space charge below transition or the chamber inductance above it) are analytically described by means of reduction of the linearized Vlasov equation…

Accelerator Physics · Physics 2021-06-16 Alexey Burov

In photoacoustic imaging, ultrasound waves generated by a temperature rise after illumination of light absorbing structures are measured on the sample surface. These measurements are then used to reconstruct the optical absorption. We…

Applied Physics · Physics 2018-12-05 Oliver Lang , Peter Kovacs , Christian Motz , Mario Huemer , Thomas Berer , Peter Burgholzer

A standard multimode optical fiber can be used as a general purpose spectrometer after calibrating the wavelength dependent speckle patterns produced by interference between the guided modes of the fiber. A transmission matrix was used to…

Optics · Physics 2017-03-30 Brandon Redding , Sebastien M. Popoff , Hui Cao