title: Deposition and characterization of silica-based films by helicon-activated reactive evaporation applied to optical waveguide fabrication.
abstract: Planar silicon dioxide optical waveguides were deposited by use of a plasma-activated reactive evaporation system, at a low deposition temperature and with reduced hydrogen contamination, on thermally oxidized silicon wafers. The deposited films show a refractive-index inhomogeneity of less than 0.1%, a thickness nonuniformity of less than 5%, and a material birefringence of approximately 5 x 10(-4). Rib-type channel waveguides were formed on the deposited films by means of hydrofluoric acid etching. The transmission loss of the rib waveguides is determined to be as low as 0.3 dB/cm at a wavelength of 1310 nm for TE polarization, after subtraction of the calculated leakage and scattering losses. Owing to the presence of the OH vibrational overtone band, an additional loss peak of 1 dB/cm is found near the 1385-nm wavelength. The experimental results of transmission loss at wavelengths of 1310 and 1550 nm are compared with analytic expressions for interface scattering and leakage loss.
authors.affiliation: Australian Photonics Cooperative Research Centre, Research School of Physical Sciences and Engineering, Australian National University, Canberra, ACT 0200, Australia. douglas.bulla@anu.edu.au
authors.forename: Douglas A P
authors.initials: DA
authors.lastname: Bulla
authors.forename: Wei-Tang
authors.initials: WT
authors.lastname: Li
authors.forename: Christine
authors.initials: C
authors.lastname: Charles
authors.forename: Rod
authors.initials: R
authors.lastname: Boswell
authors.forename: Adrian
authors.initials: A
authors.lastname: Ankiewicz
authors.forename: John
authors.initials: J
authors.lastname: Love