Light-Confining Nanoporous Anodic Alumina Microcavities by Apodized Stepwise Pulse Anodization

Abstract

Light-confining nanoporous anodic alumina microcavities by apodized stepwise pulse anodization

Realization of high-quality optical nanoporous gradient-index filters by optimal combination of anodization conditions

“…Recent developments in pulse anodization technology have aimed at improving light control quality of NAA-PCs. Optimal structural engineering of NAA-µCVs has shown that these NAA-PCs can achieve outstanding light-confining capabilities, with resonance bands achieving unprecedented quality factors as high as 113 49 and 170 50 . A variety of sinusoidal pulse anodization strategies have been explored to improve the quality of light control in NAA-GIFs, including implementation of apodization functions into anodization profiles 51 and application of anodizing voltage as a function of optical path length 52 .…”

Integrating surface plasmon resonance and slow photon effects in nanoporous anodic alumina photonic crystals for photocatalysis

“…The optical features of the characteristic PSB in NAA-PCs can be modulated with precision by engineering their nanoporous structure in the form of different PC architectures, including distributed Bragg reflectors (DBRs), 11,47 bandpass filters, 48,49 Fabry-Pérot interferometers, 50,51 gradient-index filters, 10,[52][53][54] hybrid photonic crystals, 55 and optical microcavities. [56][57][58] NAA-PCs have been used in optical chemoand biosensing, 50,51 light filtering, 47 optical encoding 54 and photocatalysis. 10,11 The nanoporous structure of NAA-PCs facilitates mass transfer of ionic and molecular species involved in photocatalytic reactions and an efficient management of photons by controlled light-matter interactions to increase photon-to-electron conversion rates for high-performance photocatalytic applications.…”

Electrochemical Engineering of Nanoporous Materials for Photocatalysis: Fundamentals, Advances, and Perspectives

“…NAA produced by anodization of aluminium is the most researched EENM in the development of PC structures. Forms of NAA-PC structures include Fabry-Pérot interferometers (NAA-FPIs) [141][142][143], distributed Bragg reflectors (NAA-DBRs) [144][145][146], gradient index filters (NAA-GIFs) [147][148][149], optical microcavities (NAA-µCVs) [158][159][160], apodized DBRs and GIFs (Apo-NAA-DBRs and Apo-NAA-GIFs) [161][162][163], bandpass filters (NAA-BPFs) [164] and linear variable bandpass filters (NAA-LVBPFs) [165]. The architecture and geometric features of NAA-PCs can be engineered with precision by pulse-like anodization under mild anodization conditions (i.e., low anodization voltage/current density and moderate acid electrolyte temperatures).…”