Analysis of the whispering gallery mode sapphire Fe3+ maser under magnetic field M. Mrad, P.Y. Bourgeois, M.E. Tobar, Y. Kersalé and V. Giordano Eur. Phys. J. Appl. Phys., 57 2 (2012) 21005 Published online: 30 January 2012 DOI: 10.1051/epjap/2012110366