A Zn-diffused Mach-Zehnder modulator on lithium niobate at 1.55-?m wavelength

Zn-diffused Mach–Zehnder intensity modulators operating at 1.55-μm wavelength are demonstrated on a z-cut and a y-cut LiNbO3 substrate for the first time. The switching voltages are measured and the corresponding values of switching voltage-length product are 9.6 V-cm and 13.5 V-cm for the z-cut and y-cut modulators, respectively. Both the modulated extinction ratios are about 20 dB. The results show that the Zn-diffused modulators not only have electro-optic tunability as great as that of the Ti-diffused ones, but also have more flexibility for device fabrication. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 43: 142–144, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20401