Dielectric microfilters are designed and developed providing
different filter functions on 3-in. substrates. Combining several coating
procedures, microlithographic techniques, and dry-etching processes,
spectral properties of basic filters are modified within patterns with feature
sizes down to 5 µm, resulting in large-area filter patterns
(>5 cm2) with multiple spectral characteristics and vertical edge profiles.
By applying these techniques within a three-step-iterative procedure red,
green, and blue filters (RGB) are arranged edge to edge on one substrate
to form a multispectral dielectric microfilter array for use as a key
component in a local resolving color sensor. These microfilters are arranged
in an array of 19 identical hexagons consisting of three rhombi
each. The number of these arrays amounts to 81 on a single 3-in. substrate.
A modular setup of a compact local resolving color sensor is
presented, consisting of Si p-i -n photoelectric cells, dielectric microfilter
arrays, an imaging lens, and a final glass cover plate with an IR-blocking