skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Nano-indentation and laser-induced damage testing in optical multilayer-dielectric gratings [Nanomechanics and laser-induced damage in optical multilayer dielectric gratings]

Abstract

Here, we demonstrate how a nanomechanical test can be used to generate metrics to complement laser-induced–damage testing (LIDT) measurements and show that differences in optical performance of the gratings (arising from changes in cleaning process and/or fabrication methods) can be related to their mechanical reliability. Data are presented on LIDT measurements in diffractive gratings of silica deposited on optical multilayers. The nano-indentation response of the diffraction gratings is measured in a new mode that allows for the extraction of a measurable metric characterizing the brittleness of the gratings, as well as their ductility. We show that lower LIDT’s are positively correlated with an increased grating brittleness, and therefore identify a nanomechanical approach to describe LIDT’s. We present extensive numerical simulations of nano-indentation tests and identify different deformation modes including stretching, shear concentration, and bending as precursors to mechanical failure in the nano-indentation test. The effects of geometrical inhomogeneities on enhanced stress generation in these gratings are specifically examined and addressed.

Authors:
 [1];  [2];  [1];  [1];  [1];  [1]
  1. Univ. of Rochester, Rochester, NY (United States)
  2. (United States)
Publication Date:
Research Org.:
Univ. of Rochester, NY (United States). Lab. for Laser Energetics
Sponsoring Org.:
USDOE National Nuclear Security Administration (NNSA)
Contributing Org.:
Laboratory for Laser Energetics, University of Rochester
OSTI Identifier:
1357217
Alternate Identifier(s):
OSTI ID: 1346875
Report Number(s):
2016-3, 1337
Journal ID: ISSN 0003-6935; APOPAI; 2016-3, 1337, 2291
Grant/Contract Number:
NA0001944
Resource Type:
Journal Article: Accepted Manuscript
Journal Name:
Applied Optics
Additional Journal Information:
Journal Volume: 56; Journal Issue: 9; Journal ID: ISSN 0003-6935
Publisher:
Optical Society of America (OSA)
Country of Publication:
United States
Language:
English
Subject:
42 ENGINEERING; 36 MATERIALS SCIENCE; diffraction gratings; silica; laser materials processing; other properties

Citation Formats

Mehrotra, K., Corning Research & Development Corp., Coming, NY, Taylor, B. N., Kozlov, A. A., Papernov, S., and Lambropoulos, J. C.. Nano-indentation and laser-induced damage testing in optical multilayer-dielectric gratings [Nanomechanics and laser-induced damage in optical multilayer dielectric gratings]. United States: N. p., 2017. Web. doi:10.1364/AO.56.002494.
Mehrotra, K., Corning Research & Development Corp., Coming, NY, Taylor, B. N., Kozlov, A. A., Papernov, S., & Lambropoulos, J. C.. Nano-indentation and laser-induced damage testing in optical multilayer-dielectric gratings [Nanomechanics and laser-induced damage in optical multilayer dielectric gratings]. United States. doi:10.1364/AO.56.002494.
Mehrotra, K., Corning Research & Development Corp., Coming, NY, Taylor, B. N., Kozlov, A. A., Papernov, S., and Lambropoulos, J. C.. Thu . "Nano-indentation and laser-induced damage testing in optical multilayer-dielectric gratings [Nanomechanics and laser-induced damage in optical multilayer dielectric gratings]". United States. doi:10.1364/AO.56.002494. https://www.osti.gov/servlets/purl/1357217.
@article{osti_1357217,
title = {Nano-indentation and laser-induced damage testing in optical multilayer-dielectric gratings [Nanomechanics and laser-induced damage in optical multilayer dielectric gratings]},
author = {Mehrotra, K. and Corning Research & Development Corp., Coming, NY and Taylor, B. N. and Kozlov, A. A. and Papernov, S. and Lambropoulos, J. C.},
abstractNote = {Here, we demonstrate how a nanomechanical test can be used to generate metrics to complement laser-induced–damage testing (LIDT) measurements and show that differences in optical performance of the gratings (arising from changes in cleaning process and/or fabrication methods) can be related to their mechanical reliability. Data are presented on LIDT measurements in diffractive gratings of silica deposited on optical multilayers. The nano-indentation response of the diffraction gratings is measured in a new mode that allows for the extraction of a measurable metric characterizing the brittleness of the gratings, as well as their ductility. We show that lower LIDT’s are positively correlated with an increased grating brittleness, and therefore identify a nanomechanical approach to describe LIDT’s. We present extensive numerical simulations of nano-indentation tests and identify different deformation modes including stretching, shear concentration, and bending as precursors to mechanical failure in the nano-indentation test. The effects of geometrical inhomogeneities on enhanced stress generation in these gratings are specifically examined and addressed.},
doi = {10.1364/AO.56.002494},
journal = {Applied Optics},
number = 9,
volume = 56,
place = {United States},
year = {Thu Mar 16 00:00:00 EDT 2017},
month = {Thu Mar 16 00:00:00 EDT 2017}
}

Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record

Save / Share:
  • Chirped pulse amplification is increasingly used to produce intense ultrashort laser pulses. When high-efficiency gratings are the dispersive element, as in the LLNL Petawatt laser, their susceptibility to laser induced damage constitutes a limitation on the peak intensities that can be reached. To obtain robust gratings, it is necessary to understand the causes of short-pulse damage, and to recognize the range of design options for high efficiency gratings. Metal gratings owe their high efficiency to their high conductivity. To avoid the inevitable light absorption that accompanies conductivity, we have developed designs for high efficiency reflection gratings that use only transparentmore » dielectric materials. These combine the reflectivity of a multilayer dielectric stack with a diffraction grating. We report here our present understanding of short-pulse laser induced damage, as it applies to dielectric gratings.« less
  • Chirped pulse amplification is increasingly used to produce intense ultrashort laser pulses. When high-efficiency gratings are the dispersive element, as in the LLNL Petawatt laser, their susceptibility to laser induced damage constitutes a limitation on the peak intensities that can be reached. To obtain robust gratings, it is necessary to understand the causes of short-pulse damage, and to recognize the range of design options for high efficiency gratings. Metal gratings owe their high efficiency to their high conductivity. To avoid the inevitable light absorption that accompanies conductivity, we have developed designs for high efficiency rejection gratings that use only transparentmore » dielectric materials. These combine the reflectivity of a multi-layer dielectric stack with a diffraction grating. We report here our present understanding of short-pulse laser induced damage, as it applies to dielectric gratings.« less
  • Here, we describe a damage testing system and its use in investigating laser-induced optical damage initiated by both intrinsic and extrinsic precursors on multilayer dielectric coatings suitable for use in high-energy, large-aperture petawatt-class lasers. We employ small-area damage test methodologies to evaluate the intrinsic damage resistance of various coatings as a function of deposition methods and coating materials under simulated use conditions. In addition, we demonstrate that damage initiation by raster scanning at lower fluences and growth threshold testing are required to probe the density of extrinsic defects, which will limit large-aperture optics performance.
  • Cited by 1