Polysilane/Polysilazane Composite: Novel Material for Optical Waveguides and Its Application to Mode-Conversion Filters

Polysilane/polysilazane (PS/PSz) composite is proposed as a novel material for optical waveguides. A refractive index change, as large as about 4.5%, can be induced and automatically built in only by UV exposure without etching and/or development due to a photochemical reaction, generally known as “photobleaching”. To verify the practical performance of the PS/PSz composite for photonic devices with refractive-index-modulated structures, we fabricated optical waveguide mode-conversion filters using polymethylphenylsilane (PMPS)/perhydropolysilazane (PHPSz) composite, and successfully demonstrated its operation in both visible (633 nm) and infrared (1310 nm) wavelength ranges. The result shows that the PS/PSz composite is a promising candidate not only for optical waveguide devices such as those used in CWDM applications, but also for optical interconnections.