Theoretical simulation shows that APE:LiNbO3 ridge waveguide can support a more tightly confined fundamental mode
than that of conventional APE or Ti-indiffused channel waveguides. Successful demonstration of such waveguides on
the surface of LiNbO3 crystal will have potential impact in the area of nonlinear integrated optics. However, the
fabrication process of ridge structures has appeared to be a challenging task. The ridge structures on the surface of X-cut
LiNbO3 crystal were fabricated by wet/dry etching process using various recipes and corresponding surface
morphologies have been closely investigated.