Millimeter-wave Ti:LiNbO/sub 3/ optical modulators

TLDR

The paper presents the design and fabrication of ridged Ti:LiNbO₃ optical modulators operating in the millimeter‑wave region, introducing a velocity‑matching design concept. The modulators are implemented as ridged Mach‑Zehnder intensity devices with a coplanar waveguide electrode, employing a velocity‑matching design and a thicker electrode with wider gaps to reduce conductor loss. Calculations show impedance matching and reduced conductor loss, and the packaged module achieves 40 Gb/s transmission with a 3.5 V half‑wave voltage and operates up to 100 GHz with a 5.1 V half‑wave voltage.

Abstract

The design, fabrication, and characteristics of ridged Ti:LiNbO/sub 3/ optical modulators that work in the millimeter-wave region are presented. A new concept of design under velocity matching is demonstrated for the proposed modulator. It has been shown by calculation that impedance matching is achieved and conductor loss is greatly reduced under velocity matching with wider gaps and a thicker coplanar waveguide electrode in conjunction with a ridge structure. Two types of Mach-Zehnder optical intensity modulators for the wavelength of 1.5 /spl mu/m are developed. A fully packaged module for 40 Gb/s transmission with a half-wave voltage of 3.5 V and a broadband modulator responsible up to 100 GHz with a half-wave voltage of 5.1 V.