Iodine Plasmonic Crystal as the Visible-Range Spectral Filter

Abstract

We analyse the optical properties of the new hyperbolic metamaterial based on the one-dimensional mesoporous aluminum oxide (Al2O3) photonic crystal film doped by metallic iodine (I2) nanoparticles. The nanocomposite is a metal-dielectric hybrid and combines the classical photonic crystal features (such as photonic bandgaps, light deceleration, negative refraction etc.) with the metallic ones (low-frequency mirroring, plasmons etc.). To get this, we propose to saturate the pores (microcavities) of the periodic aluminum oxide photonic crystal matrix synthesized by the controlled acid etching at its anonization, by the iodine vapor. This way, in the photonic crystal pores, we form the cold plasma of the iodine free electrons, and make the nanocomposite the plasmonic photonic one. Note, that the iodine saturation level defines the plasma frequency which is directly affects the crystal characteristics, so we get them easy-tunable. For example, we offer the two iodine-saturated photonic crystals with various doping level in the pass-and-reflect scheme to spectral filter the optical radiation. At last, we also wish to note that simplicity of the saturation technology makes the iodine plasmonic crystals attractive for the wide commercial usage in the large-scale optic and photonic applications and devices (such as spectral filters, optical amplifiers, high-performance selective mirrors, photonic sensors etc.).