Abstract

An integrated plasmonic indium-tin-oxide (ITO)-based silicon electro-optical modulator has been designed, fabricated, and characterized. A sandwich structure shows a 40 GHz bandwidth at the $-2$ dB level and an extinction ratio of about 1.8 dB. The device is fabricated on a silicon-on-insulator wafer. A silicon waveguide is excluded from the electric circuit. Instead, an ITO layer is used both as a bottom electrical contact and as an electric field-sensitive medium. As a gate oxide, we used a silicon dioxide layer capped with a gold top electrode to form a capacitor. The dielectric rib inside the ITO-Au capacitor forms a coupling interface between the TE photonic and plasmonic modes.

Optical modulator based on a silicon-ITO grating embedded rib structure with a tunable group delay

Swati Rajput, Vishal Kaushik, Lalit Singh, Sulabh Srivastava, and Mukesh Kumar
Opt. Lett. 46(14) 3468-3471 (2021)

Ultra-compact and broadband electro-absorption modulator using an epsilon-near-zero conductive oxide

Qian Gao, Erwen Li, and Alan X. Wang
Photon. Res. 6(4) 277-281 (2018)

Design of an ultra-compact electro-absorption modulator comprised of a deposited TiN/HfO₂/ITO/Cu stack for CMOS backend integration

Shiyang Zhu, G. Q. Lo, and D. L. Kwong
Opt. Express 22(15) 17930-17947 (2014)

Multi-layer MOS capacitor based polarization insensitive electro-optic intensity modulator

Xiaoming Qiu, Xiaoke Ruan, Yanping Li, and Fan Zhang
Opt. Express 26(11) 13902-13914 (2018)

Mid-infrared electro-optic modulator based on a graphene-embedded plasmonic rib waveguide with ultrahigh electro-optic wavelength tuning

Chenyang Hou, Tao Ma, Jinhui Gao, Heng Liu, and Fang Wang
Appl. Opt. 60(10) 2795-2802 (2021)