Complex optical filter prepared by sputter depositionM. H. Asghar, M. Shoaib, Z. M. Khan, F. Placido, S. Naseem and M. MehmoodEur. Phys. J. Appl. Phys., 49 2 (2010) 20501DOI: https://doi.org/10.1051/epjap/2009205