Development and manufacturing of multichannel filters for CCD detector of new-generation satellite for Earth observation

摘要

Abstract: In the context of new generation of Earth observation satellites, and supported by CNES REOSC has developed new kinds of interference filters placed just in front of the detector lines. Usual spectral bands B1 B2 B3 for visible and near IR range are selected separately on the same substrate by three different multidielectric coatings. Each coating forms a line of 80 millimeters length and 50 microns width, two consecutive and parallel filters being separated by 200 microns. Between each line and all around them on the total surface of the substrate, a black coating with absorbing and antireflective efficiency prevents straylight to reach the detector. The full process of manufacturing uses successive coating and engraving technics which ensure extreme precise positioning of each filter with less than 3 microns tolerances. Spectral performances go up to 85 percent of global transmittance in each spectral band and less than 1 percent of integrated rejection al over the detector sensitivity range. The spectral characteristics of these steep edges bandpass filters are completely insensitive to air-vacuum transitions and the component support with success all qualification sequences of space environment. !0