Preparation of x-cut $LiNbO_3$ Optical Waveguide and the Change in Near-field Properties according to Ti thickness

The optical near-field patterns, propagation loss and mode sizes of x-cut optical waveguide which was fabricated by Ti-diffusion varying with Ti strip thickness in wet oxygen atmosphere were discussed at optical wavelength 1550nm. As Ti thickness increased from , the insertion loss of waveguide was decreased. But at Ti thickness , mode sizes are widely broadened. The Ti thickness of below and above showed negative effects to propagation loss and fiber coupling. The best Ti thickness for fabricating low propagation loss and good fiber coupling was inferred to be between in our conditions. And for Ti thickness , its propagation loss, horizontal/vertical mode sizes were showed 1.61 dB/cm, for TM, 0.22 dB/cm, for TE respectively.