Fabrication of Y-splitters and Mach-Zehnder interferometers on (Yb, Nb):RbTiOPO 4 / RbTiOPO 4 epitaxial layers by reactive ion etching and on RbTiOPO 4 by Cs + diffusion

We present the fabrication and characterization of Y-splitters and Mach-Zehnder Interferometers by the two different techniques of reactive ion etching and ion exchange on (Yb,Nb):RbTiOPO 4 / RbTiOPO 4 and RbTiOPO 4 , respectively. Liquid phase epitaxy was used to grow planar thin films followed by reactive ion etching for fabrication of structures over it. Cs + ions were used for diffusion process because they produce a significant increase in the refractive index and the ionic radius is close to the Rb + radius. It has been found that these structures can guide light with TM polarization at 1520 nm.