Read Books Online and Download eBooks, EPub, PDF, Mobi, Kindle, Text Full Free.
Determination Of Laser Damage Initiation Probability And Growth On Fused Silica Scratches
Download Determination Of Laser Damage Initiation Probability And Growth On Fused Silica Scratches full books in PDF, epub, and Kindle. Read online Determination Of Laser Damage Initiation Probability And Growth On Fused Silica Scratches ebook anywhere anytime directly on your device. Fast Download speed and no annoying ads. We cannot guarantee that every ebooks is available!
Book Synopsis Determination of Laser Damage Initiation Probability and Growth on Fused Silica Scratches by :
Download or read book Determination of Laser Damage Initiation Probability and Growth on Fused Silica Scratches written by and published by . This book was released on 2010 with total page 10 pages. Available in PDF, EPUB and Kindle. Book excerpt: Current methods for the manufacture of optical components inevitably leaves a variety of sub-surface imperfections including scratches of varying lengths and widths on even the finest finishes. It has recently been determined that these finishing imperfections are responsible for the majority of laser-induced damage for fluences typically used in ICF class lasers. We have developed methods of engineering subscale parts with a distribution of scratches mimicking those found on full scale fused silica parts. This much higher density of scratches provides a platform to measure low damage initiation probabilities sufficient to describe damage on large scale optics. In this work, damage probability per unit scratch length was characterized as a function of initial scratch width and post fabrication processing including acid-based etch mitigation processes. The susceptibility of damage initiation density along scratches was found to be strongly affected by the post etching material removal and initial scratch width. We have developed an automated processing procedure to document the damage initiations per width and per length of theses scratches. We show here how these tools can be employed to provide predictions of the performance of full size optics in laser systems operating at 351 nm. In addition we use these tools to measure the growth rate of a damage site initiated along a scratch and compare this to the growth measured on an isolated damage site.
Book Synopsis Физика высоких слоев атмосферы, теория и методы исследования by :
Download or read book Физика высоких слоев атмосферы, теория и методы исследования written by and published by . This book was released on 1965 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Laser Induced Damage in Optical Materials by :
Download or read book Laser Induced Damage in Optical Materials written by and published by . This book was released on 1984 with total page 522 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Growth of Laser Damage in Fused Silica by :
Download or read book Growth of Laser Damage in Fused Silica written by and published by . This book was released on 2007 with total page 11 pages. Available in PDF, EPUB and Kindle. Book excerpt: Growth of laser initiated damage plays a major role in determining optics lifetime in high power laser systems. Previous measurements have established that the lateral diameter grows exponentially. Knowledge of the growth of the site in the propagation direction is also important, especially so when considering techniques designed to mitigate damage growth, where it is required to reach all the subsurface damage. In this work, we present data on both the diameter and the depth of a growing exit surface damage sites in fused silica. Measured growth rates with both 351 nm illumination and with combined 351 nm and 1054 nm illumination are discussed.
Book Synopsis Growth of Laser Initiated Damage in Fused Silica at 527 Nm by : J. N. McElroy
Download or read book Growth of Laser Initiated Damage in Fused Silica at 527 Nm written by J. N. McElroy and published by . This book was released on 2003 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The effective lifetime of optics is limited by both laser-induced damage and the subsequent growth of laser initiated damage sites. We have measured the growth rate of laser-induced damage in fused silica in both air and vacuum at 527 nm. For damage on the exit surface, the data shows exponential growth in the lateral size of the damage site with shot number. The exponential growth coefficient depends linearly on the laser fluence. The behavior at the fluence threshold for growth is contrasted to that observed at 351 nm. The growth rate was not significantly affected by either the wavelength of the initiating fluence or the presence of 10 torr of air as compared to vacuum. When the damage is located on the input surface, it has both a higher threshold for growth and does not grow exponentially.
Book Synopsis Results of Applying a Non-evaporative Mitigation Technique to Laser-initiated Surface Damage on Fused-silica by :
Download or read book Results of Applying a Non-evaporative Mitigation Technique to Laser-initiated Surface Damage on Fused-silica written by and published by . This book was released on 2010 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt: We present results from a study to determine an acceptable CO2 laser-based non-evaporative mitigation protocol for use on surface damage sites in fused-silica optics. A promising protocol is identified and evaluated on a set of surface damage sites created under ICF-type laser conditions. Mitigation protocol acceptability criteria for damage re-initiation and growth, downstream intensification, and residual stress are discussed. In previous work, we found that a power ramp at the end of the protocol effectively minimizes the residual stress (25 MPa) left in the substrate. However, the biggest difficulty in determining an acceptable protocol was balancing between low re-initiation and problematic downstream intensification. Typical growing surface damage sites mitigated with a candidate CO2 laser-based mitigation protocol all survived 351 nm, 5 ns damage testing to fluences12.5 J/cm2. The downstream intensification arising from the mitigated sites is evaluated, and all but one of the sites has 100% passing downstream damage expectation values. We demonstrate, for the first time, a successful non-evaporative 10.6?m CO2 laser mitigation protocol applicable to fused-silica optics used on fusion-class lasers like the National Ignition Facility (NIF).
Book Synopsis Initiation Identification in Fused Silica 355-nm Optics by :
Download or read book Initiation Identification in Fused Silica 355-nm Optics written by and published by . This book was released on 2006 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Thermo-mechanical surface damage initiation and growth in fused-silica 3[omega] (355nm) optics are important performance and cost issues for high-power lasers (fluences of 4-14 J/cm[sup 2]) in the few ns pulse length regime. We are working to characterize and identify the extrinsic origins of damage initiation; impurities, particulates, and manufacturing defects. We have performed a materials characterization survey approach using transmission electron microscopy to identify the chemistry and morphology of particles, and structural defects. TEM offers high chemical or elemental specificity and small analytical spot size yielding complementary materials characterization data and powerful clues to manufacturing improvements. We will report on our characterization of the near surface of one commercially manufactures fused silica optic, where the results indicate both the efficacy and potential value of this approach.
Download or read book Amṯāl Sulaimān written by and published by . This book was released on 1834 with total page 96 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Growth of Laser Initiated Damage in Fused Silica at 351 Nm by :
Download or read book Growth of Laser Initiated Damage in Fused Silica at 351 Nm written by and published by . This book was released on 2001 with total page 9 pages. Available in PDF, EPUB and Kindle. Book excerpt: The lifetime of optics in high-fluence UV laser applications is typically limited by the initiation of damage and its subsequent growth. We have measured the growth rate of laser-induced damage on fused silica surfaces in both air and vacuum. The data shows exponential growth in the lateral size of the damage site with shot number above a threshold fluence. The concurrent growth in depth follows a linear dependence with shot number. The size of the initial damage influences the threshold for growth; the morphology of the initial site depends strongly on the initiating fluence. We have found only a weak dependence on pulse length for growth rate. Most of the work has been on bare substrates but the presence of a sol-gel AR coating has no significant effect.
Book Synopsis The Effect of Pulse Duration on the Growth Rate of Laser-induced Damage Sites at 351 Nm on Fused Silica Surfaces by :
Download or read book The Effect of Pulse Duration on the Growth Rate of Laser-induced Damage Sites at 351 Nm on Fused Silica Surfaces written by and published by . This book was released on 2009 with total page 10 pages. Available in PDF, EPUB and Kindle. Book excerpt: Past work in the area of laser-induced damage growth has shown growth rates to be primarily dependent on the laser fluence and wavelength. More recent studies suggest that growth rate, similar to the damage initiation process, is affected by a number of additional parameters including pulse duration, pulse shape, site size, and internal structure. In this study, we focus on the effect of pulse duration on the growth rate of laser damage sites located on the exit surface of fused silica optics. Our results demonstrate, for the first time, a significant dependence of growth rate at 351 nm on pulse duration from 1 ns to 15 ns as [tau]{sup 0.3} for sites in the 50-100 [mu]m size range.
Book Synopsis Growth of Laser Damage in SiO2 Under Multiple Wavelength Irradiation by : M. A. Norton
Download or read book Growth of Laser Damage in SiO2 Under Multiple Wavelength Irradiation written by M. A. Norton and published by . This book was released on 2005 with total page 12 pages. Available in PDF, EPUB and Kindle. Book excerpt: In laser systems using frequency conversion, multiple wavelengths will be present on optical components. We have investigated the growth of laser initiated damage in fused silica in the presence of multiple wavelengths. In particular, we measured growth at 351 nm in the presence of 1053 nm near the threshold of growth for 351 nm alone. The data shows that the sum fluence determines the onset of growth as well as the growth rate. The measured growth coefficient is consistent with all the energy being delivered at 351 nm. Additionally, we measured growth at 527 nm in the presence of 1053 nm near the threshold of growth at 527 nm alone. In this case, the sum fluence also determines the growth coefficient but the rate is consistent with all the energy being delivered at 1053 nm. We present the measurements and discuss possible reasons for the behavior.
Book Synopsis Laser Damage Precursors in Fused Silica by :
Download or read book Laser Damage Precursors in Fused Silica written by and published by . This book was released on 2009 with total page 14 pages. Available in PDF, EPUB and Kindle. Book excerpt: There is a longstanding, and largely unexplained, correlation between the laser damage susceptibility of optical components and both the surface quality of the optics, and the presence of near surface fractures in an optic. In the present work, a combination of acid leaching, acid etching, and confocal time resolved photoluminescence (CTP) microscopy has been used to study laser damage initiation at indentation sites. The combination of localized polishing and variations in indentation loads allows one to isolate and characterize the laser damage susceptibility of densified, plastically flowed and fractured fused silica. The present results suggest that: (1) laser damage initiation and growth are strongly correlated with fracture surfaces, while densified and plastically flowed material is relatively benign, and (2) fracture events result in the formation of an electronically defective rich surface layer which promotes energy transfer from the optical beam to the glass matrix.
Book Synopsis Experimental Study of 351-nm and 527-nm Laser-initiated Surface Damage on Fused Silica Surfaces Due to Typical Contaminants by : M. A. Johnson
Download or read book Experimental Study of 351-nm and 527-nm Laser-initiated Surface Damage on Fused Silica Surfaces Due to Typical Contaminants written by M. A. Johnson and published by . This book was released on 2004 with total page 10 pages. Available in PDF, EPUB and Kindle. Book excerpt: Optics damage under high-intensity illumination may be the direct result of laser light interaction with a contaminant on the surface. Contaminants of interest are small particles of the materials of construction of large laser systems and include aluminum, various absorbing glasses, and fused silica. In addition, once a damage site occurs and begins to grow, the ejecta from the growing damage site create contamination on nearby optic surfaces and may initiate damage on these surfaces via a process we call ''fratricide.'' We report on a number of experiments that we have performed on fused silica optics that were deliberately contaminated with materials of interest. The experiments were done using 527-nm light as well as 351-nm light. We have found that many of the contaminant particles are removed by the interaction with the laser and the likelihood of removal and/or damage is a function of both fluence and contaminant size. We have developed an empirical model for damage initiation in the presence of contaminants.
Book Synopsis Laser Damage Growth in Fused Silica with Simultaneous 351 Nm and 1053 Nm Irradiation by :
Download or read book Laser Damage Growth in Fused Silica with Simultaneous 351 Nm and 1053 Nm Irradiation written by and published by . This book was released on 2008 with total page 10 pages. Available in PDF, EPUB and Kindle. Book excerpt: Laser-induced growth of optical damage often determines the useful lifetime of an optic in a high power laser system. We have extended our previous work on growth of laser damage in fused silica with simultaneous 351 nm and 1053 nm laser irradiation by measuring the threshold for growth with various ratios of 351 nm and 1053 nm fluence. Previously we reported that when growth occurs, the growth rate is determined by the total fluence. We now find that the threshold for growth is dependent on both the magnitude of the 351 nm fluence as well as the ratio of the 351 nm fluence to the 1053 nm fluence. Furthermore, the data suggests that under certain conditions the 1053 nm fluence does not contribute to the growth.
Book Synopsis Laser-induced Damage Initiated on the Surface of Particle Contaminated Fused Silica Optics at 1064nm by : Kenneth Jerome Francis Michlitsch
Download or read book Laser-induced Damage Initiated on the Surface of Particle Contaminated Fused Silica Optics at 1064nm written by Kenneth Jerome Francis Michlitsch and published by . This book was released on 1997 with total page 92 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Methods for Mitigating Growth of Laser-Initiated Surface Damage on Fused Silcia Optics at 351nm by :
Download or read book Methods for Mitigating Growth of Laser-Initiated Surface Damage on Fused Silcia Optics at 351nm written by and published by . This book was released on 2001 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: We report a summary of the surface damage, growth mitigation effort at 351nm for polished fused silica optics. The objective was to experimentally validate selected methods that could be applied to pre-initiated or retrieved-from-service optics, to stop further damage growth. A specific goal was to obtain sufficient data and information on successful methods for fused silica optics to select a single approach for processing large aperture, fused-silica optics used in high-peak-power laser applications. This paper includes the test results and the evaluation thereof, for several mitigation methods for fused silica surfaces. The mitigation methods tested in this study are wet chemical etching, cold plasma etching, CW-CO2 laser processing, and micro-flame torch processing. We found that CW-CO2 laser processing produces the most significant and consistent results to halt laser-induced surface damage growth on fused silica. We recorded successful mitigation of the growth of laser-induced surface damage sites as large as 0.5mm diameter, for 1000 shots at 351nm and fluences in the range of 8 to 13J/cm2, (almost equal to)11ns pulse length. We obtained sufficient data for elimination of damage growth using CO2 laser processing on sub-aperture representative optics, to proceed with application to large aperture ((almost equal to)40 x 40cm2) fused silica.
Book Synopsis Laser-Induced Damage of Optical Materials by : Roger M. Wood
Download or read book Laser-Induced Damage of Optical Materials written by Roger M. Wood and published by CRC Press. This book was released on 2003-08-01 with total page 252 pages. Available in PDF, EPUB and Kindle. Book excerpt: The laser power handling capacities of optical systems are determined by the physical properties of their component materials. At low intensity levels these factors are not important, but an understanding of damage mechanisms is fundamental to good design of laser products operating at high power. Laser Induced Damage of Optical Materials presents
