Reflective behavior of strong absorption metallic photonic crystals

The growing interest in fabrication and investigation of metallic photonic crystals is determined by the potential for new properties and applications. In this work, reflective spectra of strong absorption metallic photonic crystals including metal/template composites and metalic inverse opals were systematically studied. Fe-Ni alloy were electrodeposited through self-assembly templates, and inverse opals were fabricated after removal of templates. For metal/template composites, enhanced stop gap is blue shifted due to strong absorption of metallic materials. An effective fraction of alloy is introduced for the first time to describe the alloy participating in the Bragg effect, which is mainly determined by metal. However, alloy inverse opals show greater blue shift of broaden gap to high frequency regions and metallic nature in low frequency regions due to the existence of windows. Scanning electronic micrographs results indicate that there is a critical thickness of wall materials where there are windows in inverse opals. It is proposed here that windows are formed due to the associated breaking of thin alloy walls with template.