Physical vapor deposition of rare-earth doped ZrF4-based glass planar waveguides

A series of ZrF4-PbF2, and ZrF4-PbF2-ErF3 films of differing compositions w ere prepared by thermal and electron beam evaporation, using microscope gla ss slides and single crystal silicon wafers as substrates. Several crystall ization heat treatments were performed on these films, at temperatures up t o 300 degrees C. X-ray photoelectron spectroscopy was used to determine the film composition and the amorphous/crystalline state of the samples was in vestigated by X-ray diffraction. After a heat treatment of 40 min at 250 de grees C, the films were completely crystallized. The infrared absorption sp ectra of the films were recorded and their possible structures are discusse d and compared with those of ZrF4-based melted glasses. The optical propaga tion loss, measured for planar waveguides at lambda = 632.8 nm, varied betw een 1.9 and 3.5 dB/cm. The fluorescence spectrum of the I-4(3/2) --> I-4(15 /2) transition of Er3+ was recorded for a waveguide doped with 5 mol% ErF3 and the corresponding fluorescence lifetime was 1.7 ms. (C) 1999 Elsevier S cience B.V. All rights reserved.