Tunable color switch using split-ring metamaterial

We propose two designs of tunable color switch (TCS) devices, which are composed of split-ring metamaterials (SRMs). They are split-ring resonators (SRRs) floating on a mirror layer and on a complementary SRR. For convenient description, they are denoted as SRM-1 and SRM-2, respectively. The electromagnetic responses of TCS devices are investigated by comparing the geometrical parameters and surrounding refraction indexes. SRM-1 exhibits a tunable function at the wavelength of 400-450 nm, while SRM-2 shows a similar characteristic at the wavelength of 430-480 nm. Furthermore, to enhance the flexibility and applicability of proposed TCS devices, two TCS devices are exposed on the surrounding environments with different refraction indexes. These results show that SRM-1 and SRM-2 configurations exhibit the linear red-shifting of resonances by increasing the environmental refraction index. TCS devices composed of SRMs could be used in color filter, imaging sensor, refraction index sensor, etc.