PROTON-EXCHANGED AND AMMONIUM-EXCHANGED OPTICAL WAVE-GUIDES IN KTIOPO4

The potassium of KTiOPO4 has been exchanged for protons or ammonium io ns to form optical waveguides. Proton exchange is relatively fast, doe s not give depth profiles expected for diffusive processes, and distin ct potassium-depleted phases are formed. The kinetics for ammonium exc hange are relatively slow and diffusion limited, similar to those for Rb and TI exchange processes. Increases in surface refractive index of up to 0.053 for proton exchange and 0.046 for ammonium exchange have been observed, with higher values for mixed NH4/H and Rb/H exchanges.