Optical characteristics of photo-curable methacryl-oligosiloxane nano hybrid thick films
- PDF / 1,604,740 Bytes
- 8 Pages / 612 x 792 pts (letter) Page_size
- 82 Downloads / 137 Views
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 m) 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 m) 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.
I. INTRODUCTION
Planar optical devices have been of much interest in integrated planar lightwave circuit applications. Much effort has been exerted to develop planar optical devices using optically transparent materials such as silica and polymers.1,2 They were produced using various methods, such as the physical vapor deposition (PVD), chemical vapor deposition (CVD), and sol-gel processes. Among these, the sol-gel process has been considered the most practical in fabricating the planar optical devices because optically homogeneous coatings can easily be obtained at a low cost.3,4 In recent years, sol-gel-derived organic-inorganic hybrid materials (HYBRIMERs) were developed and studied for optical applications because of their excellent optical properties and relatively high thermal stabilities in comparison to general optical polymers.5,6 They also possess some very fascinating features, such as their photo-curablility and their easily tunable optical characteristics.7–11 A photo-curable HYBRIMER can be synthesized through the introduction of photo-active precursors, which usually contain C⳱C bonds. One of these photocurable HYBRIMERs is the methacryl-oligosiloxane
a)
Address all correspondence to this author. e-mail: [email protected] DOI: 10.1557/JMR.2005.0045 J. Mater. Res., Vol. 20, No. 2, Feb 2005
http://journals.cambridge.org
Downloaded: 24 Nov 2014
nano hybrid material (methacryl HYBRIMER) synthesized from 3-(trimethoxysilyl)propyl methacrylate (MPTS) and diphenylsilanediol (DPSD). MPTS has a photo-polymerizable methacryl group. DPSD contains silanol groups, which can react with the methoxy groups in MPTS. Since methanol, a byproduct of the condensation reaction between the precursors, can easily be removed through vacuum heating, a photo-curable solventless methacryl-oligosiloxane nano hybrid resin can be synthesized. The thick and crack-free methacryl HYBRIMER coating films can be obtained via a photopolymerization reaction of methacryl groups
Data Loading...
