AVS 51st International Symposium
    MEMS and NEMS Monday Sessions
       Session MN-MoP

Paper MN-MoP1
Fabrication of PLT Thin Film Waveguides by Low Temperature Two-Step Pulsed Laser Deposition Processes

Monday, November 15, 2004, 5:00 pm, Room Exhibit Hall B

Session: Poster Session
Presenter: J.-S. Kao, National Science Council, Taiwan
Authors: J.-S. Kao, National Science Council, Taiwan
D.-R. Liu, National Science Council, Taiwan
C.-H. Tsai, National Science Council, Taiwan
I.-N. Lin, Tamkang University, Taiwan
Correspondent: Click to Email
Lanthanum-modified lead titanate (PLT) thin films have attracted much attention in the application of integrated optical devices due to their high optical transparency and superior electro-optical (EO) properties. Optical signals propagation loss is the most important concern for these waveguide type devices. Because the optical absorption, scattering and leakage result from various waveguides structure defect, including PLT concentration proportion, grain boundary, surface roughness and waveguide structure, they will attenuate optical signals through the waveguide. The fabrication of PLT films have been well-developed by utilizing sputtering, chemical sol gel and excimer pulsed laser deposition (PLD) processes, whereas there is few study on the device application because of its difficulty on either wet or dry etching in microfabrication. In this study, the Pb@sub 1-x@La@sub x@TiO@sub 3@ (x = 0.28) thin films were synthesized at 150°C on MgO (100) substrates by frequency-quadrupled Nd:YAG pulsed laser (266 nm) deposition process with a defocused laser beam. Followed by 600°C post-annealing in oxygen atmosphere, the PLT planar thin film waveguides with smooth surface, high transparency and texture were produced. These characteristics were revealed by atomic force microscopy, UV/VIS/NIR spectrophotometry, and x-ray diffractometry examination. Propagation loss of the planar waveguides were measured by a prism coupler. A PLT 28 planar waveguide with a low propagation loss less than 1dB/cm was successfully prepared. Two-step PLD and lift-off processes were introduced to fabricate the ridge type channel waveguides. The light propagated properties of these waveguides were also examined by using IR (1550 nm) capture of scattered light method.