Polymer electro-optic (EO) waveguides are key component of high performance electro-optic switches. Recently, EO chromophore and host polymer matrix are investigated to get high EO coefficient (r33) and fabricate waveguide structures. To realize high r33, chromophore density in host polymer matrix must be increased. However, high loading density results in lowering of resistivity of EO material. It becomes a problem when chromophore is poled in waveguide structure and EO modulator is worked at low frequency. In this case, EO material is sandwiched by other cladding materials but usually these materials have low conductivity compared with EO material. It means effective electric field applied to EO material and r33 is reduced by cladding material layers. To improve these difficulties, we proposed new chromophore contained polymer material as cladding material of EO waveguide. Addition of EO chromospheres (6 wt %) increase conductivity to 106~107 Ω•m. The value is comparable or above to EO materials. We also present fabrication results of EO ridge waveguide with the chromophore contained cladding polymer.
Surface plasmons are coupling waves of electron and electromagnetic field at interfaces of metal and dielectrics or metallic nanostructures and localize at the boundary with nanoscale distribution. So, by using surface plasmons, one can construct integrated optical systems to overcome the diffraction limit of light. Recently, a special electromagnetic mode, called “superfocusing modes”, is important in this research area, owing to high field concentration effect due to increasing of wavenumber of surface plasmons. Metal-coat tapered optical fibers are commonly used for the probes of near-field microscopy and are suitable for fabrication of these superfocusing devices. Furthermore, when these probes are arranged face to face with nano-scale gap, the electric fields in nano-gap also can be enhanced. In this presentation, we show the fabrication processes and numerical analysis of these metal cone structures consist of tapered optical fiber pairs on chip.