Abstract
An antenna-coupled electrode electro-optic (EO) modulator exhibits potential for use in applications involving
a wireless signal receiver and a millimeter-wave sensor for 5G/beyond-5G mobile communication
systems. The suitability is primarily due to the excellent characteristics of passive and low-signal
distortion operations. With the design of the antenna-coupled electrode based on the three-dimensional
(3D) field analysis of an EO-crystal-film and a low-k glass plate stacked structure, the electric field enhancement
factor of over 8000 times of the irradiated wireless field can be obtained along a standing-
wave electrode for optical modulation, which facilitates a compact wireless-optical signal converter
without external power supply. The designed EO modulator for the 5G-band operation was fabricated
using a 50-m-thick LiNbO3 crystal film and a 250-m-thick SiO2 glass substrate and its signal conversion
characteristics were demonstrated successfully.
