Planar optical wa¨eguide polarizers for TE r TM modes 0 0 ( q q ) are fabricated on an asymmetric ion-exchanged glass Na ª K wa¨eguide. The thickness of the exchanged layer is about 2 m, achie¨ed after 2 h of the exchanged treatment, and is enough to excite a first-order mode in the layer. Polarizers are fabricated by gi¨ing the cladding of ¨arious materials on the guide surface. For TE polarization, metals 0 ( ) y 5 y¨e dielectric constant e¨aporated at 10 torr with a thickness of about 250 nm measured using the Tolansky technique are used as a clad. Metals like Al, Ag, Cu, Pb, and Au are chosen for study. For TM 0 ( ) polarization, semiconducting oxide materials q¨e dielectric constant like BaTiO , Al O , SnO , etc. are screen printed and used as a clad.
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The thicknesses of the printed films are measured by a light section microscope with an accuracy of 0.5 m, and are about 20 m. These samples are characterized using the prism-film coupling method. In the case of metal clads, the TM mode has a higher loss than the TE mode 0 0 while passing through the clad. Hence, the length where the TM r TE 0 0 loss approaches almost zero is taken as the cutoff length. On the other hand, for semiconducting clads, a slightly higher attenuation of the TE 0 mode is obser¨ed than the TM mode. Therefore, following the basic law 0 of physics, 1re times the fall of the intensity of TE is treated as the 0 cutoff condition. The cutoff lengths are obser¨ed experimentally as well as calculated theoretically. It is seen that both are in good agreement within an error of 5᎐10%. The cutoff lengths of the metals are compared with the reported ¨alues, and are analyzed on the basis of material purity and conducti¨ity.