Green luminescence in silica glass: A possible indicator of subsurface fracture

Fournier, Jessica; Néauport, Jérôme; Grua, P.; Fargin, Evelyne; Jubera, Véronique; Talaga, David; Jouannigot, Stéphane

doi:10.1063/1.3693393

Cited by 30 publications

(15 citation statements)

References 14 publications

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“…An unexplained green photoluminescence was also evidenced 17 , 18 and potentially involved in the damage initiation process. However, these photo luminescent defects were removed by an HF-based etch of 1 to 2 µm 11 , 19 . The impact of scratch morphology on the electric field distribution and its modification after etching is therefore likely to be responsible for this increase in the threshold.…”

Section: Introductionmentioning

confidence: 99%

Understanding the effect of wet etching on damage resistance of surface scratches

Fernandes

Pfiffer

Cormont

et al. 2018

Sci Rep

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Fused silica optics often exhibit surface scratches after polishing that radically reduce their damage resistance at the wavelength of 351 nm in the nanosecond regime. Consequently, chemical treatments after polishing are often used to increase the damage threshold and ensure a safe operation of these optics in large fusion-scale laser facilities. Here, we investigate the reasons for such an improvement. We study the effect of an HF-based wet etching on scratch morphology and propose a simple analytic model to reflect scratch widening during etching. We also use a finite element model to evaluate the effect of the morphological modification induced by etching on the electric field distribution in the vicinity of the scratch. We evidence that this improvement of the scratch damage resistance is due to a reduction of the electric field enhancement. This conclusion is supported by secondary electron microscopy (SEM) imaging of damage sites initiated on scratches after chemical treatment.

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Section: Introductionmentioning

confidence: 99%

Understanding the effect of wet etching on damage resistance of surface scratches

Fernandes

Pfiffer

Cormont

et al. 2018

Sci Rep

Self Cite

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“…According to L. Skuja et al . 18 , 20 , 22 , the lifetimes of these fluorescence defects discussed above are 4 ns (α-ODC(II)), 110 μs (β-ODC(II)) and 300 ns ( E δ ’), respectively. In our case (laser pulse is 6.4 ns), α-ODC(II) might be the main laser damage precursor.…”

Section: Results and Disscusionmentioning

confidence: 95%

“…Figure 3 shows the comparison of normalized fluorescence emission spectra of treated samples. There are three main peaks in the spectra at around 310 nm, 390 nm and 590 nm bands, corresponding to oxygen-deficiency centers (II) (ODC(II), around 290 nm for α band and 390 nm for β band), and E δ ’ center defects (590 nm band), respectively 18 – 20 . The characterized peak at around 310 nm band is an incomplete peak of ODCs (around 290 nm band) due to the application of filter (290 nm).…”

Section: Results and Disscusionmentioning

confidence: 99%

Surface molecular structure defects and laser-induced damage threshold of fused silica during a manufacturing process

Yan

Yang

et al. 2017

Sci Rep

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Laser induced damage of fused silica is a serious problem for high power laser systems, and damage precursors are mainly induced by manufacturing processes. In this work, fused silica samples were prepared from a manufacturing process including grinding, polishing and etching procedures. The chemical disorder of the prepared samples was inspected by using fluorescence microscopy and ultra-violet fluorescence spectrometer. The physical disorder was characterized by using Infrared and Raman spectrometer. Laser induced damage thresholds (LIDTs) were measured in R-on-1 mode by 355 nm 6.4 ns laser pulse. Results showed that with the manufacturing processes transforming from grinding to etching, the magnitude of fluorescence point defects reduced while their types did not change, the Si-O-Si bonds of prepared samples were strained and the strained bonds were mitigated. The LIDTs increased with the reducing of fluorescence defects and strained Si-O-Si bonds. However, these structural defects can not be eliminated by the current manufacturing process. Improvements may be needed to eliminate the structural defects for a higher LIDT of fused silica.

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“…They are buried in the pits, scratches and other mechanical damage in subsurface layer. In addition, studies have shown that this kind of SSDs with fluorescence characteristics is closely related to the laser damage of optics [18,19] .…”

Section: Introductionmentioning

confidence: 97%

Detection Of Surface Defects And Subsurface Defects Of Polished Optics With Multisensor Image Fusion

Sun

Wang

et al. 2022

Preprint

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Surface defects (SDs) and subsurface defects (SSDs) are the key factors decreasing the laser damage threshold of optics. Due to the spatially stacked structure, accurately detecting and distinguishing them has become a major challenge. Herein a detection method for SDs and SSDs with multisensor image fusion is proposed. The optics is illuminated by a laser under dark field condition, and the defects are excited to generate scattering and fluorescence lights, which are received by two image sensors in a wide-field microscope. With the modified algorithms of image registration and feature-level fusion, different types of defects are identified and extracted from the scattering and fluorescence images. Experiments show that two imaging modes can be realized simultaneously by multisensor image fusion, and HF etching verifies that SDs and SSDs of polished optics can be accurately distinguished. This method provides a more targeted reference for the evaluation and control of the defects of optics, and exhibits potential in the application of material surface research.

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Green luminescence in silica glass: A possible indicator of subsurface fracture

Cited by 30 publications

References 14 publications

Understanding the effect of wet etching on damage resistance of surface scratches

Understanding the effect of wet etching on damage resistance of surface scratches

Surface molecular structure defects and laser-induced damage threshold of fused silica during a manufacturing process

Detection Of Surface Defects And Subsurface Defects Of Polished Optics With Multisensor Image Fusion

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