Abstract

The ultimate goal of this research is to realize monolithic integration of active and passive. Components employing selective area doping, producing devices which are cost-effective, reproducible and marketable. To this end we compare and contrast two different techniques for the production of rare-earth doped silica waveguides. Using the solution doping technique, we have fabricated neodynium doped SiO₂-P₂O₅ waveguide lasers which achieved slope efficiencies of 2.6% (Fig. 1), output powers of over 1.5 mW and a lasing threshold of 20 mW absorbed pump power. The device length was 5.9 cm with core dimensions of 12 × 8 μm and the insertion losses measured at 632.8 nm were 1.7 dB. The results reported excel any previous reports, to the best of our knowledge, for devices of a similar nature.¹ Aerosol doping, a technique extended at Glasgow University to encompass planar technology, is discussed.² Implementing similar doping concentrations and waveguide dimensions, losses and fluorescent lifetimes are compared. The lifetimes are an important parameter providing information pertaining to the solubility and doping uniformity of the rare earth ions in the glass host. Aerosol doping, a single step process, is of particular significance as the rare-earth ions are directly incorporated into the glass soot during the deposition (Fig. 2). Consequently, it is possible to control the doping concentration through the film by governing the transfer of the aerosol to the torch during the deposition. Secondary ion mass spectroscopy results are presented illustrating the versatility and ease of vertical selective area doping. Results are also shown for regional selective area doping.

© 1994 Optical Society of America