We report on a push–pull integrated-optics Mach–Zehnder interferometer having one domain-inverted branch and one noninverted branch. It is fabricated in the c+ side of a LiNbO3 substrate. We achieve ferroelectric domain inversion in one branch of the waveguide by doping it more heavily with Ti than the other branch and by using a high-temperature treatment that raises the temperature above the doped Curie temperature of the one branch but not of the other. The cumulative electro-optic effect of the inverted branch is found to be opposite that in the noninverted branch when both are subjected to the same electric field.
© 1995 Optical Society of America
Original Manuscript: July 15, 1994
Published: February 1, 1995
Nicolas A. F. Jaeger and Lisheng Huang, "Push–pull integrated-optics Mach–Zehnder interferometer with domain inversion in one branch," Opt. Lett. 20, 288-290 (1995)