Impact of 3D-printed rods occupancy on photonic crystal transmission properties

In this study, the effect of different filling ratios on the transmission properties of rods printed by a 3D printer when using them in a photonic crystal cavity structure was investigated. First, the dielectric constant was measured experimentally for two different PLA (Polylactic Acid) and ABS (Acrylonitrile Butadiene Styrene) materials commonly used in 3D printers. Then, dielectric rods were printed with different filling ratios. The printed rod was transferred to the Lumerical FDTD software program and the photonic crystal cavity structure containing this rod was analyzed. The dispersion diagrams of the structure and the transmission spectrum were obtained. Then, these rods printed in the experimental stage were placed in the photonic crystal cavity structure containing the Alumina rod, and measurements were taken in the microwave region. As a result, it was seen that the dispersion properties of the structure were affected by the filling ratio. It was observed that with the decrease in the effective index of the rod, the band gap shifted upwards, and the bandwidth decreased, and when the rod was used in the cavity, the resonant transmission frequency shifted. This study can be a guide in determining the deviation range that occurs in designs to be made using 3D prints in communication applications.