Planar multilayer optical waveguides consisting of thin dielectric films with metal cladding have been investigated as TM-mode absorption polarizers. Two types of structure are analyzed. In the first one, the guided-mode losses were calculated as a function of the thicknesses of the buffer layer and the metal. Another polarizer, utilizing a MgF2/metal/MgF2 overlayer, is discussed. It is observed that in this configuration TM absorption losses are enhanced and thus we get a better extinction ratio. The polarizer has also been fabricated and characterized on ion exchange optical planar waveguides with a MgF2/Ag/MgF2 overlayer.