Subwavelength plasmonic color printing enabled by diatom-inspired metamaterials

The light manipulation performance of plasmonic structures has been widely studied at wavelengths spanning from microwave and terahertz radiation to infrared and visible light. Plasmonic nanostructures with designed sizes and geometries displays strong enhancement and confinement of electromagnetic fields that known for tailoring spectra. By exploiting these properties, color printing at the diffraction limit in the visible light regime has recently been demonstrated. Diatoms, one kind of unicellular microalgae, widely exist in aquatic environments and are well-known for their light-manipulating properties. The abundant biologically evolved micro- and nano-pores enable diatom frustules to be remarkably studied achieving superior optical performances in sensing and solar cell applications. In this work, the diatom-inspired metamaterials for subwavelength plasmonic color printing have been investigated. The nanoporous structures on diatom frustules are examined to develop both Hierarchical Diatom-inspired Nanopattern (HDN) and Misaligned Hierarchical Diatom-inspired Nanopattern (MHDN) with different structural parameters on the metamaterial design. Using finite-element simulations, the practical metal-insulator-metal (MIM) configurations are screened, and electric field distribution is evaluated to uncover the physical mechanisms responsible for color printing. Nanofabrication and optical measurement are conducted as complementary validation for simulation analysis and present the practicality for application.2024-01-15T00:00:00