Channel waveguides and Mach-Zehnder structures on RbTiOPO4 by Cs ion exchange

Cs ion exchange in RbTiOPO4 and (Yb,Nb):RTP/RTP(001) has been used to locally increase the refractive indices for waveguide circuit fabrication. Ti masks were fabricated on RTP samples by conventional photolithography. Cs exchange was done using a CsNO3 melt at 698 K during 2 h. Elemental analysis confirms an Cs profile with a variable depth. Apparently the Cs exchange is disfavored in the doped epitaxial sample. The refractive index variation is higher for nz than for nx,y. Nearfield images of the guided modes at 633, 1064 and 1520 nm were recorded. The optical characterization shows propagation losses of 5 dB/cm at 1520 nm. ©2015 Optical Society of America OCIS codes: (130.2790) Guided waves; (130.3130) Integrated optics materials. References and links 1. P. A. Thomas, S. C. Mayo, and B. E. Watts, “Crystal structures of RbTiOAsO4, KTiO(P0.58,As0.42)O4, RbTiOPO4 and(Rb0.465,K0.535)TiOPO4, and analysis of pseudosymmetry in crystals of the KTiOPO4 family,” Acta Crystallogr. 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