Abstract
Zircon can be amorphised by ion implantation and the damaged layer is of a lower refractive index than the original crystal. This index change has been used to define optical waveguides. Data are presented on the refractive-index profiles, their dose dependence and the effects of different implant temperatures. Annealing studies reveal an interesting pattern in which below 350-degrees-C the index change is reduced, but at higher temperatures it is re-established. The details of the annealing effects are dose dependent. A defect model is discussed. Finally, the possibility of rare-earth doped zircon laser waveguides is mentioned.