scholarly journals Development of a Frequency Tunable Green Laser Source for Advanced Virgo+ Gravitational Waves Detector

Galaxies ◽  
2020 ◽  
Vol 8 (4) ◽  
pp. 87
Author(s):  
Camilla De Rossi ◽  
Jonathan Brooks ◽  
Julia Casanueva Diaz ◽  
Antonino Chiummo ◽  
Eric Genin ◽  
...  
Keyword(s):  
Gravitational Waves ◽  
Optical Cavity ◽  
Green Laser ◽  
Laser Source ◽  
Acquisition Strategy ◽  
Frequency Tunable ◽  
One Year

After one year of data taking, the observing run three (O3), we are preparing for an improved version of the system, named the Advanced Virgo plus. One of the major upgrades will be the installation of the signal recycling mirror to form an additional optical cavity and improve the sensitivity of the interferometer. This also requires a change in the lock acquisition strategy. In particular, the arms will be locked at the beginning with lasers at a different wavelength from the main one. Such a strategy has already been implemented and tested in LIGO and KAGRA, and in this paper we will present how it has been conceived in Virgo.

scholarly journals Interferometer Sensing and Control for the Advanced Virgo Experiment in the O3 Scientific Run

Galaxies ◽  
2020 ◽  
Vol 8 (4) ◽  
pp. 85
Author(s):  
Annalisa Allocca ◽  
Diego Bersanetti ◽  
Julia Casanueva Diaz ◽  
Camilla De Rossi ◽  
Maddalena Mantovani ◽  
...  
Keyword(s):  
Gravitational Waves ◽  
Laser Interferometer ◽  
Control Strategies ◽  
New Techniques ◽  
Binary Neutron Star ◽  
2Nd Generation ◽  
The Third ◽  
Binary Black Hole ◽  
One Year ◽  
And Control

Advanced Virgo is a 2nd-generation laser interferometer based in Cascina (Italy) aimed at the detection of gravitational waves (GW) from astrophysical sources. Together with the two USA-based LIGO interferometers they constitute a network which operates in coincidence. The three detectors observed the sky simultaneously during the last part of the second Observing Run (O2) in August 2017, and this led to two paramount discoveries: the first three-detector observation of gravitational waves emitted from the coalescence of a binary black hole system (GW170814), and the first detection ever of gravitational waves emitted from the coalescence of a binary neutron star system (GW170817). Coincident data taking was re-started for the third Observing Run (O3), which started on 1st April 2019 and lasted almost one year. This paper will describe the new techniques implemented for the longitudinal controls with respect to the ones already in use during O2. Then, it will present an extensive description of the full scheme of the angular controls of the interferometer, focusing on the different control strategies that are in place in the different stages of the lock acquisition procedure, which is the complex sequence of operations by which an uncontrolled, “free” laser interferometer is brought to the final working point, which allows the detector to reach the best sensitivity.

scholarly journals ANALISIS PERBANDINGAN KINERJA KEUANGAN PERUSAHAAN SEBELUM DAN SESUDAH AKUISISI

2018 ◽  
Vol 7 (5) ◽  
pp. 2323
Author(s):  
Putu Yulia Kumalasari Dewi ◽  
Ni Putu Santi Suryantini
Keyword(s):  
Financial Performance ◽  
T Test ◽  
Corporate Financial Performance ◽  
Financial Condition ◽  
Analysis Technique ◽  
Before And After ◽  
Acquisition Strategy ◽  
One Year ◽  
A Company ◽  
Paired T Test

Financial performance is a reflection of the financial condition of a company. The purpose of this study is to determine the significance of differences in corporate financial performance before and after the acquisition of mining acquisition companies in the BEI period 2011-2013 by analyzing financial performance one year before and one year after acquisition. The method of determining the sample is the census that the entire population is used as a sample which is obtained by 5 acquirer companies. The analysis technique used is paired t-test (Pair-Sample T-test). Based on the results of the analysis found that financial performance measured by five financial ratios of CR, ROA, DER, TATO, PER that did not differ significantly after acquisition compared to before acquisition. The acquisition strategy has not been fully achieved due to the condition of financial performance after the acquisition has not increased. The motive of the acquisition is not economic but non-economic. The acquirer company which to achieve success, must make preparations by looking at the conditions of the company to be taken over.

Compact green laser source using butt-coupling between multi-section DFB-laser and SHG waveguide crystal

2008 ◽  
Vol 44 (25) ◽  
pp. 1463 ◽  
Author(s):  
J. Wiedmann ◽  
O. Brox ◽  
T. Tekin ◽  
F. Scholz ◽  
T. Büttner ◽  
...  
Keyword(s):  
Green Laser ◽  
Laser Source ◽  
Dfb Laser ◽  
Butt Coupling

20.2: High-Efficiency Green Laser Source for Compact Projectors

2009 ◽  
Vol 40 (1) ◽  
pp. 265 ◽  
Author(s):  
John Khaydarov ◽  
Andrei Shchegrov ◽  
Stepan Essaian ◽  
Greg Nemet ◽  
Suren Soghomonyan ◽  
...  
Keyword(s):  
High Efficiency ◽  
Green Laser ◽  
Laser Source

73.4L: Late-News Paper: Miniature, Highly Efficient, and Low Cost Green Laser Source for Pico-Projectors

2011 ◽  
Vol 42 (1) ◽  
pp. 904-907
Author(s):  
Stepan Essaian ◽  
John Khaydarov ◽  
Slav Slavov ◽  
Gevorg Gabrielyan ◽  
Armen Poghosyan ◽  
...  
Keyword(s):  
Low Cost ◽  
Green Laser ◽  
Laser Source ◽  
Highly Efficient ◽  
Late News

Ophthalmological Diagnostic Complex Based on a Slit Lamp and Multi-Waves Laser

10.12737/2742 ◽  
2013 ◽  
Vol 20 (4) ◽  
pp. 109-113
Author(s):  
Соболев ◽  
Yu. Sobolev ◽  
Иванов ◽  
A. Ivanov ◽  
Астахов ◽  
...  
Keyword(s):  
Anterior Segment ◽  
Green Laser ◽  
Laser Source ◽  
Slit Lamp ◽  
Laser Trabeculoplasty ◽  
Medical Institutions ◽  
Medical Diagnostic ◽  
Stereoscopic Observation ◽  
Diagnostic Complex ◽  
Technical Features

The paper presents the ophthalmological diagnostic complex based on slit lamp, equipped with equipment for laser pa-nretinal photocoagulation. Pre-existing principle of construction of the ophthalmologic lasers involves a cascade of work of waves of different length, while in the new version of the device the ability to use two waves simultaneously and implementation of adjustment of the intensity of each wavelength. Pattern-scanning laser ophthalmo-coagulator works at two wavelengths 532 nm and 810 nm. Use of multi-waves laser source expands the range of possible applications in the treatment of retinal diseases. Medical-diagnostic complex is intended for stereoscopic observation, investigation of the anterior segment of the eyeball, lens, retina in medical, medical-preventive and research medical institutions and private clinics. This device allows to effectively conduct operations as pattern retinal laser photo-coagulation and laser trabeculoplasty green laser, and transpupilar thermotherapy of choroidal neovascularization, transcleral retinal photocoagulation and ciliary body by means of infrared (IR) laser. In the multi-colored photocoagulator, the technologies of "automatic positioning of the field of coagulation"(PASCAL) are used. The paper discusses the technical features of the instrument and its development prospects.

scholarly journals Frequency Tuning Characteristics of a High-Power Sub-THz Gyrotron with Quasi-Optical Cavity

Electronics ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 526
Author(s):  
Xiaotong Guan ◽  
Jiayi Zhang ◽  
Wenjie Fu ◽  
Dun Lu ◽  
Tongbin Yang ◽  
...  
Keyword(s):  
Magnetic Field ◽  
High Power ◽  
Frequency Tuning ◽  
Optical Cavity ◽  
Separation Distance ◽  
Center Frequency ◽  
Broad Bandwidth ◽  
Particle In Cell ◽  
Power Frequency ◽  
Frequency Tunable

Motivated by some emerging high-frequency applications, a high-power frequency-tunable sub-THz quasi-optical gyrotron cavity based on a confocal waveguide is designed in this paper. The frequency tuning characteristics of different approaches, including magnetic field tuning, mirror separation adjustment, and hybrid tuning, have been investigated by particle-in-cell (PIC) simulation. Results predict that it is possible to realize a smooth continuous frequency tuning band with an extraordinarily broad bandwidth of 41.55 GHz, corresponding to a relative bandwidth of 18.7% to the center frequency of 0.22 THz. The frequency tunability is provided by varying the separation distance between two mirrors and correspondingly adjusting the external magnetic field. During the frequency tuning, the output power remains higher than 20 kW, which corresponds to an interaction efficiency of 10%. Providing great advantages in terms of broad bandwidth, smooth tuning, and high power, this research may be conducive to the development of high-power frequency-tunable THz gyrotron oscillators.

scholarly journals Physical and Geometrical Properties of Additively Manufactured Pure Copper Samples Using a Green Laser Source

Materials ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3642
Author(s):  
Samira Gruber ◽  
Lukas Stepien ◽  
Elena López ◽  
Frank Brueckner ◽  
Christoph Leyens
Keyword(s):  
Electrical Conductivity ◽  
Eddy Current ◽  
Pure Copper ◽  
Current Method ◽  
Negative Influence ◽  
Green Laser ◽  
Laser Source ◽  
Eddy Current Method ◽  
Geometrical Properties ◽  
Laser Systems

So far, copper has been difficult to process via laser powder bed fusion due to low absorption with the frequently used laser systems in the infrared wavelength range. However, green laser systems have emerged recently and offer new opportunities in processing highly reflective materials like pure copper through higher absorptivity. In this study, pure copper powders from two suppliers were tested using the same machine parameter sets to investigate the influence of the powder properties on the material properties such as density, microstructure, and electrical conductivity. Samples of different wall thicknesses were investigated with the eddy-current method to analyze the influence of the sample thickness and surface quality on the measured electrical conductivity. The mechanical properties in three building directions were investigated and the geometrical accuracy of selected geometrical features was analyzed using a benchmark geometry. It could be shown that the generated parts have a relative density of above 99.95% and an electrical conductivity as high as 100% International Annealed Copper Standard (IACS) for both powders could be achieved. Furthermore, the negative influence of a rough surface on the measured eddy-current method was confirmed.

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