title: Effect of water vapor in a y-cut lithium niobate waveguide.
abstract: In z-cut lithium niobate (LiNbO3) samples, surface damage has been observed after diffusion in a wet atmosphere, but recent reports show that with controlled flow of water vapor waveguides with good surface morphology and low loss can be obtained. Y-cut waveguides do not show any surface damage. Fabrication of y-cut waveguides diffused with controlled variation of water vapor in the ambient has not been reported to the best of our knowledge. We show that a minimum loss in y-cut waveguides is obtained at a particular water vapor content in the ambient, which is lower than the loss obtained for waveguides diffused in dry ambient. We have found a decrease in the waveguide loss to 0.3 dB/cm from 0.6 dB/ cm for 1 mL of water vapor passed per hour as compared with a dry atmosphere.
authors.forename: M
authors.initials: M
authors.lastname: Ahmad
authors.forename: K
authors.initials: K
authors.lastname: Chelapathi
authors.forename: Y G
authors.initials: YG
authors.lastname: Patro