Effects of various polishing media and techniques on the surface finish and behavior of laser glasses Page: 4 of 28
This article is part of the collection entitled: Office of Scientific & Technical Information Technical Reports and was provided to Digital Library by the UNT Libraries Government Documents Department.
The following text was automatically extracted from the image on this page using optical character recognition software:
A more persistent problem common to these glasses is their low resist-
ance to laser damage at their surfaces.. This low damage threshold is reduced
further when these surfaces are coated. Properly controlled laser damage
tests generally confirm that the damage threshold decreases in the following
order: bulk glass (highest), bare entry surface, bare exit surface, coated
entry surface, and coated exit surface (lowest). Laser pulse duration and
wavelength can affect this order.1 The lower damage threshold of the exit
surface as compared to the entrance surface is attributed to a greater
optical electric-field strength at the exit surface.2 Conflicting results
and lack of consistent evidence still prevent adequate explanation of the
lower damage threshold for bar and coated surfaces as compared to their
bulk glass damage threshold. Surface damage is generally attributed to
surface finish and various techniques have been tried to obtain imperfection-
free surfaces.3 No improvement in damage threshold is anticipated after
achieving surface roughness (rms) of < 100 A.4 Surface damage threshold
could also be affected by a variety of other surface related features as
dust particles, surface films, embedded polishing particles, subsurface
scratches and cracks, and residual stresses.4-7
An investigation was initiated this summer at LL; to evaluate the
polishing procedures used to prepare our laser glass components. In this
document, we report some of our findings on polishing compound,, subsurface
defects, surface chemistry of the polished glass, and techniques developed
to evaluate glass surfaces. Since this is an ongoing study, we will also
comment on the direction being taken as a result of existing data.
This investigation is divided into three parts; (1) evaluation of exist-
ing processes, (2) laboratory-scale experiments on modified processes, and
Here’s what’s next.
This article can be searched. Note: Results may vary based on the legibility of text within the document.
Tools / Downloads
Get a copy of this page or view the extracted text.
Citing and Sharing
Basic information for referencing this web page. We also provide extended guidance on usage rights, references, copying or embedding.
Reference the current page of this Article.
Landingham, R.L.; Casey, A.W. & Lindahl, R.O. Effects of various polishing media and techniques on the surface finish and behavior of laser glasses, article, November 7, 1978; Livermore, California. (https://digital.library.unt.edu/ark:/67531/metadc1203356/m1/4/: accessed March 24, 2019), University of North Texas Libraries, Digital Library, https://digital.library.unt.edu; crediting UNT Libraries Government Documents Department.