Presentation + Paper
15 November 2019 Creating sub angstrom surfaces on planar and spherical substrates
J. Nelson, S. Iles
Author Affiliations +
Proceedings Volume 11175, Optifab 2019; 1117505 (2019)
Event: SPIE Optifab, 2019, Rochester, New York, United States
Sub-Angstrom surfaces are frequently specified by customers requiring increased optical and energy efficiency, with most stringent requirements from applications in the UV and from certain high power laser systems. Much research has been performed to understand related surface dynamics, with considerable amounts of information published on precision finishing of optical glass. Many suppliers of low roughness surfaces rely on finishing methods that create subsurface damage through the aggressive removal of material. While the magnitude of this damage can be minimized through the use of progressively finer abrasives, detectable levels of latent structure are still evident. However, finishing processes that merely wipe clean the Beilby layer without disturbing the substrate produce nearly perfect surfaces with little to no subsurface damage. This has been the focus of development efforts at Edmund Optics. By careful management of process variables, extremely smooth surfaces lacking subsurface damage have been demonstrated in fused silica and N-BK7 materials. Applications for optics having these characteristics are found in automotive, defense, medical, and industrial domains. This paper discusses results achieved for producing sub-Angstrom surfaces on fused silica and N-BK7 glass. Surfaces with measured roughness of 0.5Å have consistently been demonstrated on fused silica, with results of around 0.8Å shown for N-BK7. Types of processes useful for achieving these results will be discussed, along with basic metrology methods for producing reliable sub-Angstrom measurements.
Conference Presentation
© (2019) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
J. Nelson and S. Iles "Creating sub angstrom surfaces on planar and spherical substrates", Proc. SPIE 11175, Optifab 2019, 1117505 (15 November 2019);
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Spherical lenses

Surface finishing




Energy efficiency

High power lasers

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