High-quality-factor anodic alumina optical microcavities prepared by cyclic anodizing with voltage versus optical path length modulation

Anodic alumina optical microcavities with precisely tuned positions of intense resonance bands within the range of 250-1500 nm are prepared by cyclic anodizing with voltage versus optical path length modulation. Among the structures obtained by anodizing, the fabricated optical microcavities possess an unprecedentedly high quality factor of 209-269.