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The next generation of adaptive optics (AO) systems will require tomographic reconstruction techniques to map the optical refractive index fluctuations, generated by the atmospheric turbulence, along the line of sight to the astronomical…

Instrumentation and Methods for Astrophysics · Physics 2014-01-07 H. W. Shepherd , J. Osborn , R. W. Wilson , T. Butterley , R. Avila , V. S. Dhillon , T. J. Morris

This paper discusses the multi-wavelength scanning Raman lidar being built at Lidar Division, CEILAP (CITEDEF-CONICET) in the frame of the Argentinean Cherenkov Telescope Array (CTA) collaboration to measure the spectral characteristics of…

Instrumentation and Methods for Astrophysics · Physics 2019-08-14 Juan Pallotta , Pablo Ristori , Lidia Otero , Fernando Chouza , Delia Raul , Francisco Gonzalez , Alberto Etchegoyen , Eduardo Quel

We present a compact and lightweight 1.5 {\mu}m lidar using a free-running single-photon detector (SPD) based on a multi-mode fiber (MMF) coupling InGaAs/InP negative feedback avalanche diode. The ultimate light detection sensitivity of SPD…

Applied Physics · Physics 2018-11-14 Chao Yu , Jiawei Qiu , Haiyun Xia , Xiankang Dou , Jun Zhang , Jian-Wei Pan

The luminosities of protostars provide one of the only indirect methods of measuring their masses and mass accretion rates in their earliest stages of evolution. Accurate measurements of protostellar luminosities traditionally requires…

Solar and Stellar Astrophysics · Physics 2026-04-14 Michael M. Dunham , Aina Palau , Nuria Huélamo , Eduard I. Vorobyov , Zach Yek , Sean Rand

The sodium laser guide star adaptive optics system ALFA, which is installed at the Calar Alto 3.5-m telescope, has been undergoing an intensive optimisation phase. Observations using natural guide stars that are presented in this paper,…

Astrophysics · Physics 2007-05-23 R. I. Davies , W. Hackenberg , T. Ott , A. Eckart , S. Rabien , S. Anders , S. Hippler , M. Kaspar

Wavefront sensing with a thin diffuser has emerged as a potential low-cost alternative to a lenslet array for aberrometry. Diffuser wavefront sensors (DWS) have previously relied on tracking speckle displacement and consequently require…

Optics · Physics 2019-01-01 Gregory N. McKay , Faisal Mahmood , Nicholas J. Durr

We demonstrate the use of an optimized 5 core photonic lantern (PL) to simultaneously measure tip/tilt errors at the telescope focal plane, while also providing the input to an instrument. By replacing a single mode (SM) fiber with the PL…

Instrumentation and Methods for Astrophysics · Physics 2018-09-24 Mark K. Corrigan , Timothy J. Morris , Robert J. Harris , Theodoros Anagnos

Tunable lasers are essential for optical communication, spectroscopy, and precision sensing, where flexible and fast control of the laser wavelength is needed. However, conventional tunable laser systems often rely on mechanical actuation,…

Light detection and ranging (LiDAR) has been utilized for optimizing wireless communications due to its ability to detect the environment. This paper explores the use of LiDAR in channel estimation for wideband multi-user…

Signal Processing · Electrical Eng. & Systems 2025-03-19 Haotian Zhang , Shijian Gao , Xiang Cheng , Liuqing Yang

A tunable diode laser spectrometer has been employed to examine the overtone absorption lines of $^{12}$CH$_4$ in the region around 12780 cm$^{-1}$ (780 nm) at room temperature. The spectrometer sources are commercially available tunable…

Chemical Physics · Physics 2022-02-10 A. Lucchesini

We herein report a simultaneous frequency stabilization of two 780-nm external cavity diode lasers using a precision wavelength meter (WLM). The laser lock performance is characterized by the Allan deviation measurement in which we find…

Advances in high-resolution laser spectroscopy have enabled many scientific breakthroughs in physics, chemistry, biology and astronomy. Optical frequency combs have pushed measurement limits with ultrahigh-frequency accuracy and…

Optics · Physics 2023-03-27 Shuangyou Zhang , Toby Bi , Pascal Del'Haye

Laser guide stars (LGS) are used in many adaptive optics systems to extend sky coverage. The most common wavefront sensor used in combination with a LGS is a Shack-Hartmann wavefront sensor (SHWFS). The Shack-Hartmann has a major…

Instrumentation and Methods for Astrophysics · Physics 2020-12-07 Sebastiaan Y. Haffert , Christoph U. Keller , Richard Dekany

Wavefront sensors encode phase information of an incoming wavefront into an intensity pattern that can be measured on a camera. Several kinds of wavefront sensors (WFS) are used in astronomical adaptive optics. Amongst them, Fourier-based…

Large-scale structure (LSS) analysis in galaxy surveys is a powerful cosmological probe but is limited by tracer bias, which can obscure underlying information and weaken parameter constraints. Existing methods either model bias or restrict…

Cosmology and Nongalactic Astrophysics · Physics 2025-12-01 Zhujun Jiang , Xiaolin Luo , Wenying Du , Zhiwei Min , Fenfen Yin , Longlong Feng , Jiacheng Ding , Le Zhang , Xiao-Dong Li

Semiconductor mode-locked lasers can be used in a variety of applications ranging from multi-carrier sources for WDM communication systems to time base references for metrology. Their packaging in compact chip- or module-level systems…

WL measurements have well-known shear estimation biases, which can be partially corrected for with the use of image simulations. We present an analysis of simulated images that mimic HST/ACS observations of high-redshift galaxy clusters,…

Cosmology and Nongalactic Astrophysics · Physics 2020-08-26 B. Hernandez-Martin , T. Schrabback , H. Hoekstra , N. Martinet , J. Hlavacek-Larrondo , L. E. Bleem , M. D. Gladders , B. Stalder , A. A. Stark , M. Bayliss

Light detection and ranging (LiDAR) is a ubiquitous tool to provide precise spatial awareness in various perception environments. A bionic LiDAR that can mimic human-like vision by adaptively gazing at selected regions of interest within a…

Stable narrow-linewidth light sources play a significant role in many precision optical systems. Electro-optic laser frequency stabilization systems, such as the well-known Pound-Drever-Hall (PDH) technique, have been key components of…

Optics · Physics 2024-03-05 Mohamad Hossein Idjadi , Kwangwoong Kim

We present a solid-state laser system that generates over 200 mW of continuous-wave, narrowband light, tunable from 316.3 nm - 317.7 nm and 318.0 nm - 319.3 nm. The laser is based on commercially available fiber amplifiers and optical…

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