Recent developments of multispectral filter assemblies for CCD, CMOS and bolometer

Breakthrough spectrophotometric instrument for the ultra-fine characterization of the spectral transmittance of thin-film optical filters

“…Since the end of the 1990s, the simultaneous availability of powerful optical filter design software [1][2][3][4] and reliable thin-film deposition techniques using energetic processes [5][6][7] such as ion beam assistance, ion beam sputtering or magnetron sputtering have made possible the manufacture of high performance optical interference coatings comprising a great number of layers, from one hundred [8] up to a few thousand [9,10]. For highly demanding applications such as observation of the Earth from space [11,12], wavelength multiplexing of high data rate optical telecommunications channels [13,14], study of the organization of living matter at the cellular scale [15], or interferometric detection of gravitational waves [16,17], it is necessary to confirm by very accurate measurements the theoretical figures provided by the design, especially for some key filter parameters like optical density in the blocking regions, steepness of band edges, or wavelength and angle resolved scattering.…”

Micromirrors with controlled amplitude and phase

“…However, the decrease of the size of the coated area is also challenging and presents wide interest for example for the development of striped filters (e.g. for bolometers [9]), pixelated filters [10] or for laser beam shaping [11]. In this paper, we present the design, fabrication and characterization of mirrors deposited on half of a fused silica, with high reflectivity (>99%) and a phase shift between the mirror and the uncoated substrate equal to π/2 at 1064 nm [12].…”

Multispectral filters assemblies for earth remote sensing imagers

“…Sodern manufacturing process [1] consists of assembling frames and stripe filters by the slice with a black structural glue to build the overall multispectral filter assembly as shown in Fig. 1 hereafter.…”