Design and Fabrication of a Visible-Light-Compatible, Polymer-Based Photonic Crystal Resonator and Waveguide for Sensing Applications

In this paper, we have proposed a polymer-based photonic crystal (PhC) resonator, with multiple sizes of cavities, and a waveguide to be used as highly sensitive optical sensor components. Properties of the proposed PhC were simulated by the finite-difference time-domain method, and the polymer-based PhC resonator and waveguide were fabricated on a photoresist (polymer) by electron beam lithography, which was prepared on an Au-layer-deposited Si substrate. We detected the resonant light that penetrated through the waveguide and was trapped in the PhC resonator. Optical characteristics of the fabricated PhC were evaluated by detecting the polymer layer deposition process by using the layer-by-layer (LbL) method to deposit polymer layers. As a result, by using an optimized design of a polymer-based PhC resonator with a long cavity (equivalent to a defect of three holes), the PhC structure changes caused by LbL deposition lead to changes in resonant light wavelength (peak shift: 5.26 nm/layer). Therefore, we suggest that a PhC resonator and a waveguide is applicable as an optical sensor.