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

Micromachines ◽  
2021 ◽  
Vol 12 (10) ◽  
pp. 1226
Author(s):  
Wanli Zhang ◽  
Feng Shi ◽  
Ci Song ◽  
Ye Tian ◽  
Yongxiang Shen

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.

Materials ◽  
2020 ◽  
Vol 13 (6) ◽  
pp. 1294
Author(s):  
Yaoyu Zhong ◽  
Yifan Dai ◽  
Feng Shi ◽  
Ci Song ◽  
Ye Tian ◽  
...  

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.


2020 ◽  
Vol 10 (23) ◽  
pp. 8496
Author(s):  
Thomas Gischkat ◽  
Daniel Schachtler ◽  
Igor Stevanovic ◽  
Zoltan Balogh-Michels ◽  
Roelene Botha ◽  
...  

Substrate cleaning prior to coating has a strong influence on the performance of the optical component. Exemplary, none or inadequate cleaning reduces the resistance against laser irradiation drastically. Especially in laser components coated with anti-reflective layers, the interface between substrate and coating is one of the most limiting factors. This study investigates different precision cleaning processes and their influence on the laser resistance of ion-beam sputtered anti-reflective coatings. Therefore, a SiO2/Ta2O5 multilayer anti-reflective coating for a wavelength of 1064 nm and a normal angle of incidence was deposited onto high-quality fused silica substrates. Prior to deposition, the substrates were cleaned with various cleaning processes using different solutions and ultrasonic frequencies. To characterize the cleaned surface quality, the surfaces were analyzed with respect to root-mean-square (RMS) roughness and particle density. Laser damage was measured using a 1064 nm ns-pulsed laser test bench. It was found that an alcoholic pre-clean is recommendable to prevent laser damage caused by organic films remaining from the polishing process. The applied ultrasonic frequencies strongly influenced the particle density down to the sub-micrometer range and in consequence, the laser-induced damage threshold (LIDT). Ultrasonic cleaning at excessive power levels can reduce laser resistance.


2017 ◽  
Vol 25 (23) ◽  
pp. 29260 ◽  
Author(s):  
Mingjin Xu ◽  
Feng Shi ◽  
Lin Zhou ◽  
Yifan Dai ◽  
Xiaoqiang Peng ◽  
...  

RSC Advances ◽  
2018 ◽  
Vol 8 (57) ◽  
pp. 32417-32422
Author(s):  
Laixi Sun ◽  
Ting Shao ◽  
Jianfeng Xu ◽  
Xiangdong Zhou ◽  
Xin Ye ◽  
...  

RIBE and DCE techniques can be combined to tracelessly mitigate laser damage precursors on a fused silica surface.


Silicon ◽  
2019 ◽  
Vol 12 (2) ◽  
pp. 425-432 ◽  
Author(s):  
Hui Ye ◽  
Yaguo Li ◽  
Qiao Xu ◽  
Wei Yang ◽  
Chen Jiang

Open Physics ◽  
2018 ◽  
Vol 16 (1) ◽  
pp. 539-543
Author(s):  
Jiangmei Zhang ◽  
Xiang Gao ◽  
Kunpeng Wang ◽  
Youyong Liu ◽  
Xiuhong Yang ◽  
...  

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.


2016 ◽  
Author(s):  
Mathilde Pfiffer ◽  
Philippe Cormont ◽  
Jérôme Néauport ◽  
Sébastien Lambert ◽  
Evelyne Fargin ◽  
...  

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