Title :
Spectral-domain analysis of coplanar waveguide traveling-wave electrodes and their applications to Ti:LiNbO3 Mach-Zehnder optical modulators
Author :
Kawano, Kenji ; Kitoh, Tsutomu ; Jumonji, Hiromichi ; Nozawa, Toshinori ; Yanagibashi, Mitsuaki ; Suzuki, Toshio
Author_Institution :
NTT Corp., Kanagawa, Japan
fDate :
9/1/1991 12:00:00 AM
Abstract :
Hybrid-mode and quasi-TEM analyses are carried out for coplanar waveguide traveling-wave electrodes applicable to z-cut Ti:LiNbO3 optical modulators. The analyses are based on the spectral-domain approach. The microwave effective index and the characteristic impedance are clarified, together with the microwave conductor loss. These are incorporated to accurately predict the modulator characteristics. It is shown that these characteristics can be greatly improved by employing a thicker buffer layer. High-speed and low-driving-power Ti:LiNbO3 optical modulators are realized at 1.52 μm wavelength. Agreement between the calculated and measured results is good
Keywords :
electro-optical devices; lithium compounds; optical modulation; optical waveguide components; optical waveguide theory; titanium; 1.52 micron; CPW; LiNbO3:Ti; Mach-Zehnder optical modulators; buffer layer; characteristic impedance; coplanar waveguide; microwave conductor loss; microwave effective index; quasiTEM analysis; spectral-domain approach; traveling-wave electrodes; z-cut; Buffer layers; Conductors; Coplanar waveguides; Electrodes; High speed optical techniques; Impedance; Optical buffering; Optical losses; Optical modulation; Optical waveguides;
Journal_Title :
Microwave Theory and Techniques, IEEE Transactions on
