Broadband electro-optical modulator based on transparent conducting oxide.

We report a broadband electro-optical (EO) modulator based on tunable plasmonic metamaterial. Transparent conducting oxides provide an excellent active plasmonic material for optoelectronic applications. By utilizing our indium-tin-oxide- (ITO) based multilayer structure, light absorption of the active ITO layer can be electrically modulated over a large spectrum range. Based on the attenuated total reflectance configuration, bias polarity-dependent modulation up to 37% has been experimentally demonstrated. This EO modulator has advantages of simple design, easy fabrication, compact size, broadband performance, large modulation depth, as well as compatibility with existing silicon photonics platforms.