Figuring of fused silica optical surface with thin parts by plasma chemical vaporization machining

2019 ◽  
Author(s):  
Hideo Takino ◽  
Kazuya Yamamura ◽  
Yasuhisa Sano ◽  
Yuzo Mori
Keyword(s):  
Fused Silica ◽  
Optical Surface ◽  
Plasma Chemical

scholarly journals Full Aperture CO2Laser Process to Improve Laser Damage Resistance of Fused Silica Optical Surface

2014 ◽  
Vol 2014 ◽  
pp. 1-5 ◽  
Author(s):  
Wei Liao ◽  
Chuanchao Zhang ◽  
Xiaofen Sun ◽  
Lijuan Zhang ◽  
Xiaodong Yuan
Keyword(s):  
Damage Threshold ◽  
Fused Silica ◽  
Processing Temperature ◽  
Test Results ◽  
Optical Surface ◽  
Improved Method ◽  
Damage Resistance ◽  
Scanning Velocity ◽  
High Laser ◽  
Laser Flux

An improved method is presented to scan the full-aperture optical surface rapidly by using galvanometer steering mirrors. In contrast to the previous studies, the scanning velocity is faster by several orders of magnitude. The velocity is chosen to allow little thermodeposition thus providing small and uniform residual stress. An appropriate power density is set to obtain a lower processing temperature. The proper parameters can help to prevent optical surface from fracturing during operation at high laser flux. S-on-1 damage test results show that the damage threshold of scanned area is approximately 40% higher than that of untreated area.

scholarly journals Plasma enhanced chemical vapor deposition of gallium phosphide at low temperature

2021 ◽  
Vol 2103 (1) ◽  
pp. 012122
Author(s):  
A V Uvarov ◽  
I A Morozov ◽  
A I Baranov ◽  
A A Maximova ◽  
E A Vyacheslavova ◽  
...  
Keyword(s):  
Low Temperature ◽  
Vapor Deposition ◽  
Gallium Phosphide ◽  
Smooth Surface ◽  
Chemical Deposition ◽  
Chemical Vapor ◽  
Fused Silica ◽  
Rf Plasma ◽  
Silicon Substrates ◽  
Plasma Chemical

Abstract This article is devoted to the formation and study of the properties of amorphous gallium phosphide layers obtained by plasma-chemical deposition at a temperature of 250 °C. The optical and structural properties of the obtained layers on fused silica and silicon substrates were investigated. The possibility of the formation of a homogeneous amorphous gallium phosphide with a smooth surface at a low temperature and low power of RF plasma was shown.

KOH-based shallow etching for exposing subsurface damage and increasing laser damage resistance of fused silica optical surface

2020 ◽  
Vol 108 ◽  
pp. 110249
Author(s):  
Laixi Sun ◽  
Ting Shao ◽  
Xinda Zhou ◽  
Fenfei Li ◽  
Shufan Chen ◽  
...  
Keyword(s):  
Fused Silica ◽  
Subsurface Damage ◽  
Laser Damage ◽  
Optical Surface ◽  
Damage Resistance

Low‐temperature low‐stress silicon nitride for optoelectronic Applications prepared by electron cyclotron resonance plasma Chemical‐vapor deposition

1996 ◽  
Vol 446 ◽  
Author(s):  
S. Belkouch ◽  
D. Landheer ◽  
R. Taylor ◽  
K. Rajesh ◽  
G. I. Sproule
Keyword(s):  
Silicon Nitride ◽  
Electron Cyclotron Resonance ◽  
Chemical Vapor ◽  
Fused Silica ◽  
Plasma Chemical ◽  
Plasma Chemical Vapor Deposition ◽  
Silicon Nitride Films ◽  
Waveguide Loss ◽  
Substrate Temperatures ◽  
Resonance Plasma

AbstractSilicon nitride films have been deposited with a single‐magnet electron‐resonance deposition system using nitrogen and silane as the reaction gases at substrate temperatures of 110°C and 300°C. The films are slightly nitrogen‐rich with no measurable Si‐H bonds measurable by Fourier Transform infrared spectroscopy and the concentration of hydrogen present as N‐H bonds increases with increasing SiH4/N2. The stress levels in the films can be controlled from tensile to compressive by decreasing the SiH4/N2 flow ratio and very low stress can be obtained with N‐H bond concentrations of 4 at. %. The optical bandgap for the layer with the lowest stress value (‐11.5 MPa), deposited at 300°C was 4.9 eV, as determined from a taue plot, and the waveguide loss at 632.8 nm was 2.3 dB/cm for 500 nm thick film deposited on fused silica.

scholarly journals Reaction ion etching process for improving laser damage resistance of fused silica optical surface

2016 ◽  
Vol 24 (1) ◽  
pp. 199 ◽  
Author(s):  
Laixi Sun ◽  
Hongjie Liu ◽  
Jin Huang ◽  
Xin Ye ◽  
Handing Xia ◽  
...  
Keyword(s):  
Fused Silica ◽  
Etching Process ◽  
Laser Damage ◽  
Optical Surface ◽  
Ion Etching ◽  
Damage Resistance

Variation of the amount of hydrogen along the galactic ridge

1967 ◽  
Vol 31 ◽  
pp. 171-172
Author(s):  
Th. Schmidt-Kaler
Keyword(s):  
Surface Brightness ◽  
Milky Way ◽  
Neutral Hydrogen ◽  
Line Of Sight ◽  
Optical Surface ◽  
Hydrogen Density ◽  
Continuous Radiation ◽  
Galactic Longitude

The integralNHof neutral-hydrogen density along the line of sight is determined from the Kootwijk and Sydney surveys. The run ofNHwith galactic longitude agrees well with that of thermal continuous radiation and that of the optical surface brightness of the Milky Way.

SEM analysis of DC magnetron sputtered beryllium films

1988 ◽  
Vol 46 ◽  
pp. 960-961
Author(s):  
E. F. Lindsey ◽  
C. W. Price ◽  
E. L. Pierce ◽  
E. J. Hsieh
Keyword(s):  
Fine Structure ◽  
Electron Emission ◽  
Secondary Electron ◽  
Low Voltage ◽  
Ion Beam ◽  
Secondary Electron Emission ◽  
Sem Analysis ◽  
Fused Silica ◽  
Grain Structure ◽  
Silica Substrate

Columnar structures produced by DC magnetron sputtering can be altered by using RF biased sputtering or by exposing the film to nitrogen pulses during sputtering, and these techniques are being evaluated to refine the grain structure in sputtered beryllium films deposited on fused silica substrates. Beryllium is brittle, and fractures in sputtered beryllium films tend to be intergranular; therefore, a convenient technique to analyze grain structure in these films is to fracture the coated specimens and examine them in an SEM. However, fine structure in sputtered deposits is difficult to image in an SEM, and both the low density and the low secondary electron emission coefficient of beryllium seriously compound this problem. Secondary electron emission can be improved by coating beryllium with Au or Au-Pd, and coating also was required to overcome severe charging of the fused silica substrate even at low voltage. The coating structure can obliterate much of the fine structure in beryllium films, but reasonable results were obtained by using the high-resolution capability of an Hitachi S-800 SEM and either ion-beam coating with Au-Pd or carbon coating by thermal evaporation.

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