scholarly journals The possibilities of using a femtosecond fiber laser in the manufacture of thermionic cathodes

2021 ◽  
pp. 67-72
Keyword(s):  
Fiber Laser ◽  
Emission Characteristics ◽  
Solid Structure ◽  
Plasma Sputtering ◽  
Thermionic Cathodes ◽  
Ion Plasma ◽  
Cathode Assembly ◽  
Made In ◽  
Femtosecond Fiber Laser

The possibilities of using a fiber laser with a femtosecond duration of radiation pulses in the manufacture of miniature thermionic cathodes made of 50 μm of tungsten-rhenium foil are shown. The cathode assembly, consisting of a heater and a core, is made in the form of a solid structure with an oxidecoating applied by ion-plasma sputtering. The emission characteristics of the cathode are presented.

scholarly journals Micro-hole drilling and cutting using femtosecond fiber laser

2014 ◽  
Vol 53 (5) ◽  
pp. 051513 ◽  
Author(s):  
Huan Huang ◽  
Lih-Mei Yang ◽  
Jian Liu
Keyword(s):  
Fiber Laser ◽  
Hole Drilling ◽  
Micro Hole ◽  
Femtosecond Fiber Laser

INFLUENCE OF THE COMPOSITION OF THE RADIO-FREQUENCY SPUTTERING ATMOSPHERE ON THE DENSITY OF STATES AND INTERBAND LIGHT ABSORPTION IN THIN Y2O3 FILMS

2021 ◽  
Vol 88 (6) ◽  
pp. 881-886
Author(s):  
O. M. Bordun ◽  
I. O. Bordun ◽  
I. M. Kofliuk ◽  
I. Yo. Kukharskyy ◽  
I. I. Medvid
Keyword(s):  
Absorption Band ◽  
Density Of States ◽  
Interband Absorption ◽  
Long Wavelength ◽  
Plasma Sputtering ◽  
Radio Frequency Sputtering ◽  
Ion Plasma ◽  
Quasi Classical Approximation ◽  
Heavily Doped ◽  
Interband Light Absorption

The long-wavelength edge of the fundamental absorption band of thin Y2O3 films obtained by radiofrequency ion-plasma sputtering is investigated. The edge of interband absorption after annealing of the films in an atmosphere of argon, oxygen, or a mixture of these gases is shown to be approximated well by the Urbach empirical rule. Diffractograms of the obtained films were studied and a model of a heavily doped or defective semiconductor in the quasi-classical approximation was used to analyze the experimental results. This model allows determining the radius of the basic electronic state, the screening radius, and the rootmean-square potential depending on the sputtering atmosphere.

High-energy femtosecond fiber laser at 1.6 microns for corneal surgery

2010 ◽  
Author(s):  
Franck Morin ◽  
Frédéric Druon ◽  
Marc Hanna ◽  
Patrick Georges
Keyword(s):  
Fiber Laser ◽  
High Energy ◽  
Corneal Surgery ◽  
Femtosecond Fiber Laser

scholarly journals Physical model of «substrate-coating» system structuring in complex modification processes of surface layers in working parts of dies and press molds

2018 ◽  
Vol 2018 (11) ◽  
pp. 35-41
Author(s):  
Олег Морозов ◽  
Oleg Morozov ◽  
Валерий Кокорин ◽  
Valeriy Kokorin ◽  
Владимир Табаков ◽  
...  
Keyword(s):  
Plastic Deformation ◽  
Physical Model ◽  
Cold Plastic Deformation ◽  
Coating System ◽  
Resistant Steel ◽  
Surface Layers ◽  
Heat Resistant Steel ◽  
Plasma Sputtering ◽  
Ion Plasma ◽  
Wear Coatings

Basic methods to increase durability of die working parts including processes of cold plastic deformation at anti-wear coatings application by a method of ion-plasma sputtering are considered. A physical model of cold plastic deformation of samples made of heat-resistant steel H12M is presented.

scholarly journals Применение покрытий AlN для защиты поверхности гетероструктур системы AlGaAs/GaAs от взаимодействия с атмосферным кислородом

2020 ◽  
Vol 46 (6) ◽  
pp. 16
Author(s):  
Е.В. Фомин ◽  
А.Д. Бондарев ◽  
И.П. Сошников ◽  
N.B. Bercu ◽  
L. Giraudet ◽  
...  
Keyword(s):  
Protective Coatings ◽  
Residual Pressure ◽  
Aluminum Oxynitride ◽  
Effective Protection ◽  
Pure Nitrogen ◽  
Plasma Sputtering ◽  
Laser Heterostructures ◽  
Ion Plasma ◽  
Thin Aluminum ◽  
Film Substrate

The paper presents the results of the synthesis of thin aluminum nitride films by reactive ion-plasma sputtering and the study of their properties with the aim of using as the protective coatings for the high-power AlxGa1-xAs/GaAs semiconductor laser heterostructures. EDS studies and ellipsometry showed that at a residual pressure in the chamber of the order of ~10-5 Torr, a layer of aluminum oxynitride is formed in the films. In this case, the film-substrate heterointerface can undergo oxidation. However, AlN films with a thickness of the order of 100 nm grown in a pure nitrogen medium with a residual pressure of ~10-7 Torr apparently do not contain oxygen, and can reliably prevent its penetration into the heterointerface region. Potentially, they can serve as effective protection for oxidation sensitive heterostructures.

scholarly journals Топография поверхности и оптические характеристики тонких пленок AlN на подложке GaAs (100), полученных методом реактивного ионно-плазменного распыления

2019 ◽  
Vol 45 (5) ◽  
pp. 38
Author(s):  
Е.В. Фомин ◽  
А.Д. Бондарев ◽  
A.I. Rumyantseva ◽  
T. Maurer ◽  
Н.А. Пихтин ◽  
...  
Keyword(s):  
Atomic Force Microscopy ◽  
Refractive Index ◽  
Surface Structure ◽  
Optical Characteristics ◽  
Process Conditions ◽  
Antireflection Coatings ◽  
Force Microscopy ◽  
Plasma Sputtering ◽  
Atomic Force ◽  
Ion Plasma

AbstractA study of the surface topography and optical characteristics of thin AlN films used as passivating and antireflection coatings deposited on n -GaAs (100) substrates by reactive ion-plasma sputtering is reported. It was found that the process conditions affect the structure and the optical characteristics of the films, which makes it possible to obtain coatings with prescribed parameters. An analysis of the results furnished by ellipsometry and atomic-force microscopy of the surface shows that the refractive index of the films is correlated with the surface structure.

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