A core-cladding waveguide structure for the a-axis Nd:MgO: LiNbO3 sing
le crystal fiber with parabolic refractive index profiles was achieved
by a Mg-ion indiffusion process. Propagation loss coefficient of the
cladded crystal fiber was measured and is 7 times lower than the uncla
dded crystal fibers. Transmission modes of the 60 mu m x 45 mu m cladd
ed crystal fiber were observed and the low order modes propagation was
obtained.