Fluoride damage to substrates during stripping of mirrors

Autor: Brian DuPraw, David Hilyard, Daren Dillon, Donald T. Gavel, Renate Kupke, Andrew C. Phillips
Rok vydání: 2014
Předmět:
Zdroj: Advances in Optical and Mechanical Technologies for Telescopes and Instrumentation.
ISSN: 0277-786X
DOI: 10.1117/12.2056887
Popis: Fluorides are useful low-index materials that can be used to enhance reflectivity of over-coated metallic films. In particular, YF3 has been suggested as a useful low-stress low-index material in the IR where film layers must be thicker, and it has also been found to enhance durability in silver-based mirrors. However, if these mirrors need to be stripped for recoating, care must be taken with the stripping process to avoid damaging a silica-based substrate through production of hydrofluoric acid. We present data that such damage can occur, and discuss empirically-derived alternative stripping processes in place of the normal acid-based approach to mitigate the danger.
Databáze: OpenAIRE