MEGARA Optics: Stain removal in PBM2Y prisms

D. Aguirre-Aguirre, R. Izazaga-Pérez, B. Villalobos-Mendoza, E. Carrasco, A.G. De Paz, J. Gallego, J. Iglesias

Research output: Chapter in Book/Report/Conference proceedingConference contribution


MEGARA is the new integral-field and multi-object optical spectrograph for the GTC. For medium and high resolution, the dispersive elements are volume phase holographic gratings, sandwiched between two flat windows and two prisms of high optical precision. The prisms are made of Ohara PBM2Y optical glass. After the prisms polishing process, some stains appeared on the surfaces. For this, in this work is shown the comparative study of five different products (muriatic acid, paint remover, sodium hydroxide, aqua regia and rare earth liquid polish) used for trying to eliminate the stains of the HR MEGARA prisms. It was found that by polishing with the hands the affected area, and using a towel like a kind of pad, and polish during five minutes using rare earth, the stains disappear completely affecting only a 5% the rms of the surface quality. Not so the use of the other products that did not show any apparent result.

Original languageEnglish
Title of host publicationJournal of Physics: Conference Series
PublisherInstitute of Physics Publishing
Publication statusPublished - 8 Mar 2017
Externally publishedYes

Publication series

NameJournal of Physics: Conference Series
PublisherIOP Publishing Ltd.
ISSN (Print)1742-6588

All Science Journal Classification (ASJC) codes

  • General Physics and Astronomy


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