Evaluation of microstructure characteristics of lithium niobate single-crystal fiber with magnesium-ion-indiffused cladding

A magnesium ion indiffusion process is applied to lithium niobate single-crystal fibers. Electron probe microanalysis show that magnesium ions have diffused into the bulk of the ctystal fibers and the magnesium ion concentration in the magnesium-diffused Layer has an approximately parabolick profile, which corresponds to that of theoretical simulation. It is shown by conventional X-ray diffraction and scanning electron microscopy that a good starting single crystal of the magnesium-diffused crystal fiber can be preserved by controlling suitable diffusion parameters such as diffusion temperature, diffusion time, and MgO film thickness, etc., to ensure the completeness of magnesium ion indiffusion, but the magnesium-diffused region etches differently from virgin-region crystals.