OPTICAL FILTER WITH MULTILAYER STRUCTURE OF ANODIC ALUMINIUM OXIDE AND METHOD OF FORMATION THEREOF BY MEANS OF ANODISING Russian patent published in 2020 - IPC G02B5/26 C25D11/04 

FIELD: physics.

SUBSTANCE: invention relates to photonics, more specifically to methods of producing photonic crystals, photonic crystal heterostructures and optical filters capable of reflecting a given portion of the spectrum of electromagnetic radiation. Object of the invention is an optical filter with properties of a Bragg reflector with a multilayer structure of porous anodic aluminium oxide with cyclic variation of pore density in the direction of the normal to the surface of the filter and a method for production thereof. Allowance for dissolution of pore walls during anodizing determines the main difference between the presented optical filters, which consists in arrangement of pore density extremes in the direction of the normal to the surface of the filter and in use when obtaining voltage dependence on the length of the optical path, which is calculated directly during anodizing.

EFFECT: technical result is high Q-factor of optical filter reflection and transmission peaks.

19 cl, 1 tbl, 9 dwg