DETERMINATION OF DIFFUSION PROFILES OF NEODYMIUM IN LITHIUM-NIOBATE BY MEANS OF SPATIALLY-RESOLVED FLUORESCENCE MEASUREMENTS

The application of spatially resolved measurements of fluorescence int ensity to the determination of diffusion profiles, in this case of neo dymium ions into lithium niobate, and to the concentration dependence of the fluorescence lifetime is discussed. The technique permits a pre cise determination of diffusion depth, but extraction of detailed poin t-by-point concentration measurements is not possible. A detailed anal ysis of the effect on the accuracy of the method of systematic uncerta inties, including quantum electrodynamical corrections and concentrati on-dependent lifetimes, is given. The overall systematic error in meas urement of diffusion coefficient is shown to be approximately 10%. The diffusion coefficients measured are consistent with previous values, but the fluorescence lifetimes obtained are probably shorter than for bulk-doped Nd:LiNbO3.