Characteristics of Er-doped Ak(2)O(3) thin films deposited by reactive co-sputtering

Er-doped Al2O3 thin films have been deposited by reactive co-sputtering ont o thermally oxidized Si-wafers. The deposition process has been optimized w ith respect to the requirements originating from the application of these m ultilayer structures as integrated optical amplifiers for the third telecom window, i.e., the wavelength range 1.52-1.56 mu m. The films obtained at a substrate temperature of only 400 degrees C are amorphous and show a homog enous structure, without columns or grains. For slabguides, background loss es smaller than 0.25 dB/cm have been obtained, even without any annealing. A relatively broad luminescence band, having an FWHM of similar to 55 nm ar ound the 1.533-mu m wavelength, has been measured. From gain versus pumping power curves, an upconversion coefficient lower then 20.10(-25) m(3)/s has been derived, being half of the values reported up to now in the literatur e. Simulations based on experimentally determined material parameters and a ssuming a channel attenuation of 0.5 dB/cm indicate, for 0.24 at.% Er chann el devices with an optimal channel length of 7.7 cm, an amplification of 8 dB at 1.533 mu m for a pump wavelength of 1.48 mu m, and a pump power of on ly 8.7 mW.