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

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.

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Argon plasma etching of fused silica substrates for manufacturing high laser damage resistance optical interference coatings

Optical Materials Express ◽

10.1364/ome.7.003598 ◽

2017 ◽

Vol 7 (10) ◽

pp. 3598 ◽

Cited By ~ 15

Author(s):

Kęstutis Juškevičius ◽

Rytis Buzelis ◽

Giedrius Abromavičius ◽

Romanas Samuilovas ◽

Saulė Abbas ◽

...

Keyword(s):

Plasma Etching ◽

Argon Plasma ◽

Fused Silica ◽

Laser Damage ◽

Optical Interference ◽

Damage Resistance ◽

High Laser ◽

Silica Substrates

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Detection of the damage threshold of fused silica components and morphologies of repaired damage sites based on the beam deflection method

Open Physics ◽

10.1515/phys-2018-0070 ◽

2018 ◽

Vol 16 (1) ◽

pp. 539-543

Author(s):

Jiangmei Zhang ◽

Xiang Gao ◽

Kunpeng Wang ◽

Youyong Liu ◽

Xiuhong Yang ◽

...

Keyword(s):

Damage Threshold ◽

Repair Process ◽

Fused Silica ◽

Beam Deflection ◽

Laser Damage Threshold ◽

Laser Damage ◽

Online Assessment ◽

Damage Resistance ◽

Damage Repair

Abstract This article proposes a method to quickly detect the damage threshold of the fused silica components and the characteristics of the repair point damage. With a device detecting the beam deflection, the laser damage threshold is detected, quickly and effectively. Then, based on the beam deflection though mitigated sites, the beam deflection signals of the damage repair points are measured and the morphologies of mitigated sites are analyzed. This method is helpful in the online assessment of the damage resistance of the downstream optics and provides the guidance of the repair process.

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Study on the Absorption Characteristics and Laser Damage Properties of Fused Silica Optics under Flexible Polishing and Shallow DCE Process

Micromachines ◽

10.3390/mi12101226 ◽

2021 ◽

Vol 12 (10) ◽

pp. 1226

Author(s):

Wanli Zhang ◽

Feng Shi ◽

Ci Song ◽

Ye Tian ◽

Yongxiang Shen

Keyword(s):

Chemical Etching ◽

Ion Beam ◽

Damage Threshold ◽

Fused Silica ◽

Laser Damage ◽

Damage Resistance ◽

Etching Depth ◽

Treatment Processes ◽

Laser Induced Damage ◽

Combined Technique

The enhancement of laser damage resistance of fused silica optics was a hotspot in scientific research. At present, a variety of modern processes have been produced to improve the laser induced damage threshold (LIDT) of fused silica optics. They included pre-treatment processes represented by flexible computer controlled optical surfacing (CCOS), magnetorheological finishing (MRF), ion beam finishing (IBF), and post-treatment processes represented by dynamic chemical etching (DCE). These have achieved remarkable results. However, there are still some problems that need to be solved urgently, such as excessive material removal, surface accuracy fluctuation in the DCE process, and the pollution in MRF process, etc. In view of above problems, an MRF, CCOS, IBF and shallow DCE combined technique was used to process fused silica optics. The surface morphology could be greatly controlled and chemical etching depth was reduced, while the LIDT increased steadily. After processing by this combined technique, the LIDT increased to 12.1 J/cm2 and the laser damage resistance properties of fused silica were significantly enhanced. In general, the MRF, IBF, CCOS and shallow DCE combined technique brought much help to the enhancement of laser damage resistance of fused silica, and could be used as a process route in the manufacturing process of fused silica.

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Effects of Ion Beam Etching on the Nanoscale Damage Precursor Evolution of Fused Silica

Materials ◽

10.3390/ma13061294 ◽

2020 ◽

Vol 13 (6) ◽

pp. 1294

Author(s):

Yaoyu Zhong ◽

Yifan Dai ◽

Feng Shi ◽

Ci Song ◽

Ye Tian ◽

...

Keyword(s):

Silica Surface ◽

Ion Beam ◽

Damage Threshold ◽

Fused Silica ◽

Structural Defects ◽

Laser Damage ◽

Material Structure ◽

Ion Beam Etching ◽

Damage Resistance ◽

Laser Induced Damage

Nanoscale laser damage precursors generated from fabrication have emerged as a new bottleneck that limits the laser damage resistance improvement of fused silica optics. In this paper, ion beam etching (IBE) technology is performed to investigate the evolutions of some nanoscale damage precursors (such as contamination and chemical structural defects) in different ion beam etched depths. Surface material structure analyses and laser damage resistance measurements are conducted. The results reveal that IBE has an evident cleaning effect on surfaces. Impurity contamination beneath the polishing redeposition layer can be mitigated through IBE. Chemical structural defects can be significantly reduced, and surface densification is weakened after IBE without damaging the precision of the fused silica surface. The photothermal absorption on the fused silica surface can be decreased by 41.2%, and the laser-induced damage threshold can be raised by 15.2% after IBE at 250 nm. This work serves as an important reference for characterizing nanoscale damage precursors and using IBE technology to increase the laser damage resistance of fused silica optics.

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Inductively Coupled Plasma Modified Silica Material Technology Research

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.483.47 ◽

2013 ◽

Vol 483 ◽

pp. 47-50

Author(s):

Li Li ◽

Ying Qian Jia ◽

Jian Li Zhao ◽

Yan Yan Gao

Keyword(s):

Plasma Etching ◽

Inductively Coupled Plasma ◽

Damage Threshold ◽

Fused Silica ◽

Material Technology ◽

Resistance Level ◽

Damage Resistance ◽

Inductively Coupled Plasma Etching ◽

Inductively Coupled ◽

Silica Material

The using inductively coupled plasma etching techniques, the surface of fused silica was etched by CF4 as etching reaction gases. The results show that the fused silica surface scratches buried defects can be effectively removed with no replication effect, with the etching process proceeds, fused silica at 355nm laser light R: 1 under irradiated, the initial damage threshold of component surface is worth to an effective improved, damage resistance level of element surface more balanced, low damage threshold is worth to significantly improve.

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