RARE-EARTH-DOPED GLASS WAVE-GUIDES PREPARED BY PULSED-LASER DEPOSITION

Rare-earth (Er,Yb) doped glass films are prepared by pulsed laser depo sition onto different substrates: Si, fused quartz and Si with a silic on oxide buffer layer. Films grown in the presence of an oxygen pressu re higher than 6 x 10(-2) mbar have a refractive index close and sligh tly higher than that of the bulk material thus proving that the densit y of the films is high. Films thicker than 1 mu m are multimode wavegu ides with a refractive index of 1.562 +/- 0.003 and show losses higher than 10 dB/cm which seem to be related to surface roughness due both to the substrate quality and the deposition process.