Four-Wave-Mixing in Zirconia-Yttria-Aluminum Erbium Codoped Silica Fiber H. Ahmad, M. C. Paul, N. A. Awang, S. W. Harun, M. Pal and K. Thambiratnam J. Eur. Opt. Soc.-Rapid Publ., 7 (2012) 12011 Published online: 08 May 2012 DOI: 10.2971/jeos.2012.12011