Novel narrow filters for imaging in the 50–150 nm VUV range
| Autor: | Juan I. Larruquert, José Antonio Méndez, Mónica Fernández-Perea, Manuela Vidal-Dasilva, José A. Aznárez |
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| Rok vydání: | 2008 |
| Předmět: | |
| Zdroj: | Astrophysics and Space Science. 320:243-246 |
| ISSN: | 1572-946X 0004-640X |
| DOI: | 10.1007/s10509-008-9798-3 |
| Popis: | GOLD (Grupo de Optica de Laminas Delgadas) is devoted to the development of novel coatings with challenging performance in the far and the extreme ultraviolet (FUV-EUV, 50–200 nm). One of the main goals of this research is to provide the communities of astronomy, solar physics and atmospheric physics with coatings with high reflectance or transmittance at a target wavelength or band, and high rejection of the out-of-band at this complicated spectral range. Above the transparency cutoff of MgF2 (115 nm), transmittance filters based on Al/MgF2 multilayers have been developed peaked at wavelengths as short as 124 nm, with a peak transmittance of 27% and a FWHM of 12 nm for a non-aged coating. Below 115 nm, a research on reflectance filters has recently started with very promising results on filters peaked at the 83.4 nm OII spectral line. Fresh filters with 27% peak reflectance at normal incidence and a FWHM of 14 nm have been obtained. Furthermore, the peak reflectance wavelength of these filters can be tuned by rotation. A filter peaked at 83 nm at normal incidence will shift to ∼73 nm at 30 deg from the normal and to ∼58 nm at 45 deg. These novel reflective filters based on Al, Yb and SiO must still demonstrate stability over time. |
| Databáze: | OpenAIRE |
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