摘要 |
<p>The invention relates to a monofrequency optical filter, including reflective elements which are formed on one surface of a dielectric support layer and which define at least one periodic array of parallel grooves passing across same. The periodicity, height, and width of said periodic groove array are selected so as to form a structure, the wavelength of which can be selected from within a predetermined range of wavelengths. According to the invention, the thickness and refractive index of the support layer are selected so that said layer forms a half-wave plate for a wavelength of the predetermined wavelength range. The filter, when in contact with the surface of the support layer opposite the surface on which the groove array is formed, includes a medium, the refractive index of which is less than that of the support layer so as to obtain a guided mode that resonates in the support layer.</p> |