Optical filter suitable for treating a ray with variable incidence and detector including such a filter

摘要

The filter has a stack of dielectric or semi-conductor layers (64, 66) arranged between two partially reflective metal end layers (70, 72). The stack of dielectric or semi-conductor layers defines an array (60) of Fabry-Perot cavities that are set at a predetermined wavelength, where an average refractive index of the dielectric or semi-conductor layers is variable in a plane orthogonal to a direction (E) of the stack so as to compensate effects of variation in angle of incidence of electromagnetic radiation on a transmission spectrum of the cavities. An independent claim is also included for an electromagnetic radiation detector comprising a plane detector circuit having an array of photosensitive elements.