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Atmospheric turbulence profile plays an important role in designing and operating adaptive optics (AO) systems with multiple laser guide stars. To obtain representative free atmospheric profiles and resolved ground layer profiles for future…

Instrumentation and Methods for Astrophysics · Physics 2023-10-17 Hajime Ogane , Yoshito Ono , Yosuke Minowa , Shin Oya , Koki Terao , Takumi Akasawa , Riki Homan , Masayuki Akiyama

The operation of a BEC based atom interferometer, where the atoms are held in a weakly-confining magnetic trap and manipulated with counter-propagating laser beams, is analyzed. A simple analytic model is developed to describe the dynamics…

Atomic Physics · Physics 2009-11-13 James A. Stickney , Rudra P. Kafle , Dana Z. Anderson , Alex A. Zozulya

We present results from a first attempt to mitigate radio frequency interference in real-time during astronomical measurements with a phased array feed on the 64 m Parkes radio telescope. Suppression of up to 20 dB was achieved despite…

Instrumentation and Methods for Astrophysics · Physics 2017-10-16 A. P. Chippendale , G. Hellbourg

This paper presents an observing methodology for calibrated measurements of radio interference levels and compare these with threshold interference limits that have been established for interference entering the bands allocated to the Radio…

Instrumentation and Methods for Astrophysics · Physics 2023-03-01 Willem A. Baan , Axel Jessner , Jaap Steenge

Data from the Palomar Testbed Interferometer, with a baseline length of 110 m and an observing wavelength of $2.2 \mu{\rm m}$, were used to derive information on atmospheric turbulence on 64 nights in 1999. The measured two-aperture…

Astrophysics · Physics 2009-11-06 R. P. Linfield , M. M. Colavita , B. F. Lane

The Keck Planet Imager and Characterizer (KPIC) is a purpose-built instrument for high-dispersion coronagraphy in the K and L bands on Keck. This instrument will provide the first high resolution (R$>$30,000) spectra of known directly…

We explore the sensitivity and completeness of long baseline interferometric observations for detecting unknown, faint companions around bright unresolved stars. We derive a linear expression for the closure phase signature of a faint…

Instrumentation and Methods for Astrophysics · Physics 2015-06-04 Jean-Baptiste Le Bouquin , Olivier Absil

A laser beam propagating to a remote target through atmospheric turbulence acquires intensity fluctuations. If the target is cooperative and provides a coherent return beam, the phase measured near the beam transmitter and adaptive optics…

Quantum-correlated interferometer is a newly emerging tool in quantum technology that offers classical-limit-breaking phase sensitivity. But to date, there exists a configurational bottleneck for its practicability due to the low…

Atomic Physics · Physics 2025-01-10 Wei Du , Shuhe Wu , Dong Zhang , Jun Chen , Yiquan Yang , Peiyu Yang , Jinxian Guo , Guzhi Bao , Weiping Zhang

Cosmological observations from ground at millimetre and sub-millimetre wavelengths are affected by atmospheric absorption and consequent emission. The low and high frequency (sky noise) fluctuations of atmospheric performance imply careful…

Instrumentation and Methods for Astrophysics · Physics 2015-06-12 Marco De Petris , Simone De Gregori , Barbara Decina , Luca Lamagna , Juan R. Pardo

Infrared interferometry has seen a revolution over the last few years. The advent of GRAVITY+ is about to enable high-contrast observations, all-sky coverage and faint science up to K=21, with the implementation on 8m-class telescope of…

Instrumentation and Methods for Astrophysics · Physics 2024-10-30 G. Bourdarot , F. Eisenhauer

Stellar intensity interferometers correlate photons within their coherence time and could overcome the baseline limitations of existing amplitude interferometers. Intensity interferometers do not rely on phase coherence of the optical…

Instrumentation and Methods for Astrophysics · Physics 2022-02-24 Sebastian Karl , Andreas Zmija , Stefan Richter , Naomi Vogel , Dmitry Malyshev , Adrian Zink , Thilo Michel , Gisela Anton , Joachim von Zanthier , Stefan Funk

After reionization, emission in the 21 cm hyperfine transition provides a direct probe of neutral hydrogen distributed in galaxies. Different from galaxy redshift surveys, observation of baryon acoustic oscillations in the cumulative 21 cm…

Cosmology and Nongalactic Astrophysics · Physics 2012-06-14 Xiao-Chun Mao

In the two decades since the first extra-solar planet was discovered, the detection and characterization of extra-solar planets has become one of the key endeavors in all of modern science. Recently direct detection techniques such as…

High precision interferometers are the building blocks of precision metrology and the ultimate interferometric sensitivity is limited by the quantum noise. Here we propose and experimentally demonstrate a compact quantum interferometer…

Quantum Physics · Physics 2020-05-20 Xiaojie Zuo , Zhihui Yan , Yanni Feng , Jingxu Ma , Xiaojun Jia , Changde Xie , Kunchi Peng

The Herbig Ae/Be star LkHalpha 101 has been imaged at high angular resolution at a number of wavelengths in the near-infrared (from 1 to 3 microns) using the Keck 1 Telescope, and also observed in the mid-infrared (11.15 microns) using the…

Astrophysics · Physics 2009-11-07 P. G. Tuthill , J. D. Monnier , W. C. Danchi , D. D. S. Hale , C. H. Townes

There are scientific and technological needs to improve the co-phasing of the primary mirrors of segmented telescopes. We have developed a methodology for using the wavefront sensor of an adaptive optics (AO) system to disentangle the phase…

Instrumentation and Methods for Astrophysics · Physics 2025-03-05 Benjamin Calvin , Michael Fitzgerald , Sam Ragland

We present an interferometric technique for measuring ultra-small tilts. The information of a tilt in one of the mirrors of a modified Sagnac interferometer is carried by the phase difference between the counter propagating laser beams.…

We study the problem of estimating the phase shift due to the general relativistic time dilation in the interference of photons using a non-linear Mach-Zender interferometer setup. By introducing two non-linear Kerr materials, one in the…

Quantum Physics · Physics 2017-10-11 Sebastian P. Kish , Timothy C. Ralph

The measurement of the close-to-the-carrier noise of rf and microwave devices is a relevant issue in time and frequency metrology and in some fields of electronics, physics and optics. While phase noise is the main concern, amplitude noise…

Instrumentation and Detectors · Physics 2009-11-11 Enrico Rubiola , Vincent Giordano