Optical characteristics of photo-curable methacryl-oligosiloxane nano hybrid thick films

In this paper, we report the fabrication the methacryl-oligosiloxane nano hybrid films from 3-(trimethoxysilyl)propyl methacrylate (MPTS) and diphenylsilanediol (DPSD), and the investigation of the tuneability of the optical characteristics of the films through the compositional change. The viscosity of the methacryl-oligosiloxane nano hybrid resin was altered at 10² intervals by the compositional modification without any drastic changes in the reaction parameters, and thickness-controlled (from 11 to 150 μm) and uniformly coated (less than 1 nm root-mean-square roughness) films were obtained through a single coating step. The refractive indices were tunable from 1.506 to 1.543, depending on composition. On the other hand, the thermo-optic coefficients remained constant (−2 × 10⁻⁴/°C), independent of composition. Also, we demonstrated a thick (170 μm) photo pattern with a high aspect ratio (3:1). Methacryl-oligosiloxane nano hybrid materials can be promising candidates for the optical applications due to easy and wide tuneability of their optical parameters.