| Optically pumped rare-earth doped dielectric waveguides can enable lossless signal routing and compact, stable, high brightness optical sources at a variety of technologically significant wavelengths. In particular, the 1530nm 4I11/2-4I15/2 Erbium and 1320nm 1G4-3H5 Praseodymium radiative transitions are well matched to the absorption loss and chromatic dispersion minima in silica fiber. The fabrication of compact devices based upon doped planar waveguides requires a host material and processing technology which are capable of achieving low propagation losses while simultaneously providing a high degree of optical activity. In this work, sputtered Al 2O3/SiO2 and ZrO2/SiO2 have been examined for potential applicability in these respects.; Erbium and praseodymium-doped planar ridge waveguides have been designed and fabricated from ion-beam sputtered Al2O3 and ZrO 2-based thin films on oxidized silicon substrates. Film deposition and doping is accomplished by co-sputtering the rare earth oxides along with the host material to provide high quality, uniformly doped films. 2-D ridge structures are defined by wet or dry plasma etching an undoped SiO2 upper cladding to provide lateral index confinement of the optical modes. The waveguide structures were designed and analyzed using a variety of numerical codes developed in this work, including a non-uniform semi-vectorial finite difference Helmholtz solver.; Experimental investigations were carried out to evaluate the physical and spectroscopic properties of these films for different doping concentrations with 980nm pumping. These include propagation loss, emission and absorption characteristics, observed radiative lifetimes of the principal transitions, and signal gain. |
