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Context. Recently our ability to study stars using asteroseismic techniques has increased dramatically, largely through the use of space based photometric observations. Work has also been done using ground based spectroscopic observations…

Solar and Stellar Astrophysics · Physics 2018-10-03 Jesper Schou

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

Since 2014, the LBT's First Light Adaptive Optics (FLAO) system has also included a seldom used capability, known as Enhanced Seeing Mode (ESM), that can improve the angular resolution over a 4' x 4' field of view (FOV). In full AO…

Instrumentation and Methods for Astrophysics · Physics 2019-11-05 Barry Rothberg , Julian C. Christou , Douglas L. Miller , Dave Thompson , Gregory E. Taylor , Christian Veillet

Optical frequency combs have revolutionized precision measurement, time-keeping, and molecular spectroscopy. A substantial effort has developed around "microcombs": integrating comb-generating technologies into compact, reliable photonic…

Blind modulation classification is an important step to implement cognitive radio networks. The multiple-input multiple-output (MIMO) technique is widely used in military and civil communication systems. Due to the lack of prior information…

Machine Learning · Computer Science 2020-04-02 Weiheng Jiang , Xiaogang Wu , Bolin Chen , Wenjiang Feng , Yi Jin

Spectrally and energy efficient orthogonal frequency division multiplexing (SEE-OFDM) is an optical OFDM technique based on combining multiple asymmetrically clipped optical OFDM (ACO-OFDM) signals into one OFDM signal. By summing different…

Information Theory · Computer Science 2015-10-29 Emily Lam , Sarah Kate Wilson , Hany Elgala , Thomas D. C. Little

A new method for examining the possible space-time variation of the fine structure constant ($\alpha$) is proposed. The technique uses a relatively simple measurement with an optical resonator to compare atom-stabilized optical frequency…

Atomic Physics · Physics 2007-05-23 J. R. Torgerson

Broadband precision spectroscopy is indispensable for providing high fidelity molecular parameters for spectroscopic databases. We have recently shown that mechanical Fourier transform spectrometers based on optical frequency combs can…

Instrumentation and Detectors · Physics 2018-05-09 Lucile Rutkowski , Piotr Maslowski , Alexandra C. Johansson , Amir Khodabakhsh , Aleksandra Foltynowicz

We have developed a wideband receiver system for simultaneous observations in CO lines of J = 2-1 and J = 3-2 transitions using the Osaka 1.85-m mm-submm telescope. As a frequency separation system, we developed multiplexers that connect…

Over the last two decades, spatial light modulators (SLMs) have revolutionised our ability to shape optical fields. They grant independent dynamic control over thousands of degrees-of-freedom within a single light beam. In this work we test…

The technique of dual modulation Faraday rotation spectroscopy has been applied for near shot-noise limited detection of HO2 at the exit of an atmospheric pressure flow reactor. This was achieved by combining direct current modulation at 51…

Optics · Physics 2015-06-17 Brian Brumfield , Wenting Sun , Yiguang Ju , Gerard Wysocki

Cell-free massive multiple-input multiple-output (mMIMO) networks enhance coverage and spectral efficiency (SE) by distributing antennas across access points (APs) with phase coherence between APs. However, the use of cost-efficient local…

Signal Processing · Electrical Eng. & Systems 2025-06-26 Yibo Wu , Luca Sanguinetti , Musa Furkan Keskin , Ulf Gustavsson , Alexandre Graell i Amat , Henk Wymeersch

Recording of transient absorption microscopy images requires fast detection of minute optical density changes, which is typically achieved with high-repetition-rate laser sources and lock-in detection. Here, we present a highly flexible and…

Over the past few years, the YOLO series of models has emerged as one of the dominant methodologies in the realm of object detection. Many studies have advanced these baseline models by modifying their architectures, enhancing data quality,…

Computer Vision and Pattern Recognition · Computer Science 2024-08-30 Yukang Huo , Mingyuan Yao , Qingbin Tian , Tonghao Wang , Ruifeng Wang , Haihua Wang

Narrow optical resonances of atoms or molecules have immense significance in various precision measurements, such as testing fundamental physics and the generation of primary frequency standards. In these studies, accurate transition…

Atomic Physics · Physics 2022-10-13 Y. -N. Lv , A. -W. Liu , Y. Tan , C. -L. Hu , T. -P. Hua , X. -B. Zou , Y. R. Sun , C. -L. Zou , G. -C. Guo , S. -M. Hu

Rydberg atomic (RA) receivers represent a revolutionary quantum technology for wireless communications, offering unprecedented sensitivity beyond conventional radio frequency (RF) antennas. However, these receivers detect only signal…

Information Theory · Computer Science 2025-08-04 Jiuyu Liu , Yi Ma , Rahim Tafazolli

We describe a new technique for heterodyne spectroscopy, which we call Least-Squares Frequency Switching, or LSFS. This technique avoids the need for a traditional reference spectrum, which--when combined with the on-source…

Astrophysics · Physics 2010-11-11 Carl Heiles

Spaceborne gravitational wave observatories, exemplified by the Laser Interferometer Space Antenna (LISA) mission, are designed to remove laser noise and clock noise from interferometric phase measurements in postprocessing. The planned…

Instrumentation and Methods for Astrophysics · Physics 2026-05-18 Kohei Yamamoto , Hannah Tomio , Charlotte Zehnder , Kenji Numata , Holly Leopardi

Frequency comb spectroscopy has significantly advanced molecular spectroscopy across scientific research and diverse applications. Among its key performance metrics especially for time-resolved studies, sensitivity and measurement speed are…

Astronomical spectrographs require frequency calibration through sources like hollow-cathode lamps or absorption-gas cells. Laser frequency combs (LFCs) provide highest accuracy but are facing operational challenges. We aim to provide a…

Instrumentation and Methods for Astrophysics · Physics 2024-09-05 Ansgar Reiners , Michael Debus , Sebastian Schäfer , Eberhard Tiemann , Mathias Zechmeister