Optical waveguides of single-crystal LiNbO3 film deposited by rf sputtering

A successful attempt in feeding a laser beam into a single-crystal LiNbO3 film deposited on a sapphire substrate by rf sputtering is described. The film thickness was 1800 Å. The loss of the film was less than 9 dB/cm at 6328 Å. The ordinary and extraordinary refractive indices of the film were no = 2.32±0.02 and ne = 2.18±0.04, respectively.