Utilize este identificador para referenciar este registo:
https://hdl.handle.net/1822/71500
Título: | Magnesium fluoride as low-refractive index material for near-ultraviolet filters applied to optical sensors |
Autor(es): | Silva, Manuel Fernando Ribeiro Pimenta, Sara Filomena Ribeiro Rodrigues, José Artur Oliveira Freitas, João Rui Martins Ghaderi, M. Gonçalves, L. M. de Graaf, G. Wolffenbuttel, R. F. Correia, J. H. |
Palavras-chave: | Optical sensors Near-ultraviolet range Thin-film optical filters Magnesium fluoride Ellipsometry Electron beam RE sputtering Optical transmittance Scanning electron microscopy Energy-dispersive X-ray spectroscopy RF sputtering |
Data: | Nov-2020 |
Editora: | Elsevier 1 |
Revista: | Vacuum |
Resumo(s): | This article describes the fabrication of MgF2 and MgO thin-film-based optical filters and compares the optical transmission of the filters over UV. The MgF2 thin-films were deposited by use of an e-beam technique and their optical properties were characterised by ellipsometry. The effect of substrate temperature on the optical properties was studied. The MgF2 optimum refractive indices were obtained with a substrate temperature between 200 degrees C and 300 degrees C. Optical simulations were performed to compare the performance of MgF2 and MgO in the fabrication of near-UV narrow bandpass optical filters. While MgO-based optical filters result in a higher transmittance peak intensity, especially at 350 nm, the MgF2 optical filters are narrower, present lower values of FWHM, a mean value of 20 nm. This feature could be especially relevant for specific applications on fluorescent optical sensors. Finally, a Fabry-Perot based on a MgF2/TiO2 optical filter was deposited, using an e-beam technique for the MgF2 thin-films and RF-sputtering technique for the TiO2 thin-films. The MgF2/TiO2 optical filter peak transmittance is approximately 70% close to 400 nm, as expected. The results are discussed with focus on applications in fluorescent optical sensors for peaks at 350, 370, 380 and 400 nm, respectively. |
Tipo: | Artigo |
URI: | https://hdl.handle.net/1822/71500 |
DOI: | 10.1016/j.vacuum.2020.109673 |
ISSN: | 0042-207X |
Versão da editora: | https://www.sciencedirect.com/science/article/pii/S0042207X20305352 |
Arbitragem científica: | yes |
Acesso: | Acesso restrito UMinho |
Aparece nas coleções: | CMEMS - Artigos em revistas internacionais/Papers in international journals |
Ficheiros deste registo:
Ficheiro | Descrição | Tamanho | Formato | |
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MSilva_Vacuum.pdf Acesso restrito! | 4,55 MB | Adobe PDF | Ver/Abrir |