Systematic Study of Electro Optic Polymers for Short-Distance Optical Interconnects

Li Zhao ^1,2,^*, Florens Kurth ^1,2, Tasja Schwenke ^2,3, Anna Karoline Rüsseler^2,4, Emil Agocs ^1,2, Hans-Hermann Johannes ^1,2, Henning Menzel ^2,3, Wolfgang Kowalsky^1,2<br/><i>¹</i><i> Institut für Hochfrequenztechnik, Technische Universität Braunschweig, Braunschweig, 38106, Germany</i><br/><i>²</i><i> Cluster of Excellence PhoenixD, Hannover, 30167, Germany</i><br/><i>³</i> <i>Institut für Technische Chemie</i><i>, Technische Universität Braunschweig, Braunschweig, 38106, Germany</i><br/><i>⁴</i><i>Laser Zentrum Hannover e.V., Hollerithallee 8, 30419 Hanover, Germany</i><br/>*E-mail address: [email protected]<br/> Electro optic (EO) polymers containing nonlinear chromophore and polymer matrix have attracted great attention due to their large EO activity. Versatile optical devices based on EO polymers like optical switch, optical modulator and so on are already reported. Compared to 1310 and 1550 nm wavelength, the EO activities at the shorter end of near-infrared range (from 800 nm to 1000 nm) for short-distance or frees-pace optical interconnects have seldom been studied due to the challenge of absorption band. The work here provides a systematic study on how the molecular engineering affects the properties of these EO polymers, as well as photonic devices. By doping chromophores up to 50 wt%, the electro-optic coefficient as a function of the concentration is examined. To suppress intermolecular interaction at higher loading concentration, site isolating groups are attached to the chromophores. Along with guest host polymers, covalently bonded polymers are also probed. They show much higher long-term temperature stability compared to guest host polymers, which is a critical figure of merit for high-density photonic device array.<br/> The advances in EO polymers make nanophotonic devices wide-band, high frequency and low energy consumption. Optical filter is an indispensable tool for nano-optic platform. Within our cooperation, the EO polymer as active material is integrated between thin-film mirrors which are prepared by ion beam sputtering. The Fabry-Perot interferometer alike device shows a promising frequency filtering and different wavelength range compared to silicon photonics.<br/> The aim of this research is to study nanophotonic EO devices starting from theoretical material design, and up to device characterization. The material data bank built by us offers a good base for optical devices over a wide range of wavelength and under extreme working conditions.<br/><b>Key words: </b>electro optic polymer, chromophore, optical device.