Optical Properties of Multi-Layer Structures of Nanometric Polymer Photonic Crystals

Abstract

Photonic crystals are attracting a lot of attention due to their ability to manipulate and guide the light. Sandwiching 3-dimensional styrene-based photonic crystals between polymeric multi-layer films such as polystyrene and polymethyl methacrylate is reported in this article. Polystyrene and polymethyl methacrylate solutions and a suspension of polymeric nano particles were cast using a specially designed spin-casting machine to produce a periodic multi-layer structure. In the next step, the optical properties of multi-layer structures were investigated via spectrophotometric techniques. A film of styrene-based nano particles has a blue-green reflection, which being affected by the suspension particles sandwiched between polystyrene and polymethyl methacrylate layers, shifts to red whereas the multi-layer structure demonstrates a green color. Moreover, the effects of the observer's viewing angle on the color shift were studied by means of goniospectrophotometric technique.

Keywords:

• Nano particles
• photonics
• poly methyl methacrylate
• polystyrene
• spin-casting