UV photoimprinting of channel waveguides on active SiO2–GeO2 sputtered thin films

We report on direct UV photoimprinting of channel waveguides on sputtered 75SiO2–25GeO2 (mol %) thin films doped with erbium and ytterbium. The films, after annealing, constitute good-quality slab waveguides, single mode at 1550nm. UV exposure through an amplitude mask defines channel waveguides. We show that the index change distribution in the channel can be simply related to the UV induced densification profile. Propagation losses are less than 0.3dB∕cm at 1300nm for both planar and channel waveguides. The fabrication procedure is simpler and cheaper than conventional technologies, so it represents a convenient way for the fabrication of low loss active optical integrated circuits.