Magnesium diffusion can be used to optimize the characteristics and performance of a Ti:LiNbO3 Mach–Zehnder modulator. Suitable use of titanium/magnesium double diffusion reduces fiber–waveguide coupling loss, minimizes the modulator size by increasing the bend radius of curvature without increasing bend losses, and decreases separation of the modulator arms. The proposed method also makes it possible to reduce the modulating voltage by improvement of guided-wave lateral confinement. Secondary ion mass spectrometry and m-line techniques are used to characterize Ti/Mg:LiNbO3 waveguides. A numerical optimization procedure based on the full vectorial beam-propagation method is presented.
© 1996 Optical Society of America
Original Manuscript: March 22, 1995
Revised Manuscript: September 26, 1995
Published: March 20, 1996
I. Mansour and F. Caccavale, "Theoretical waveguide optimization in a Ti:LiNbO3 Mach–Zehnder modulator by Mg diffusion," Appl. Opt. 35, 1492-1499 (1996)