SPECTRAL FILTER HAVING A STRUCTURED MEMBRANE AT THE SUB-WAVELENGTH SCALE, AND METHOD FOR MANUFACTURING SUCH A FILTER

摘要

The present invention, according to a first aspect thereof, relates to a spectral filter suitable for filtering an incident wave having at least one given first central wavelength ?0, said filter including a substrate having a through-opening, and a membrane made of a dielectric material. The membrane is suspended above the opening, and is structured so as to form a set of bars organized in the form of a two-dimensional pattern (33) that repeats in two directions (D1, D2), the repetition of the pattern in at least one direction being periodic or quasiperiodic, a first period (T1) being less than the central wavelength ?0.