Abstract

In the past few years rare earth ions have played an important role in the progress of optical communication technology through the development of optical amplifiers. As optical telecommunication networks are well established today the challenge lies in the development of photonic circuits with devices integrated on a single chip for generating, switching, routing and amplifying optical signals. Thus active waveguides able to perform these functions have to be deposited on a planar substrate. Incorporation of rare earth ions (Er³⁺, Pr³⁺) in thin films permits the construction of planar integrated lasers and amplifiers operating respectively at 1.5 μm and 1.3 μm, the wavelengths of interest for communication purposes. Such incorporation has been achieved mainly by means of techniques that allow local doping, such as ion exchange, in diffusion or ion implantation. While these techniques have proven to be successful, they lead to non-uniform dopant profiles and require multistep processes. Pulsed laser deposition is a recently developed technique with a proven capability for growing complex oxides.¹ It allows easily to deposit the matrix and dopant in a single step process, and leads to a uniform distribution of the dopant throughout the active region of the waveguide.²

© 1998 IEEE