Hier finden Sie wissenschaftliche Publikationen aus den Fraunhofer-Instituten.

Substantial increase in detection efficiency for filter array-based spectral sensors

: Kobylinskiy, A.; Laue, B.; Förster, E.; Höfer, B.; Shen, Y.; Hillmer, H.; Brunner, R.

Fulltext ()

Applied optics 59 (2020), No.8, pp.2443-2451
ISSN: 0003-6935
ISSN: 1539-4522
ISSN: 1559-128X
Journal Article, Electronic Publication
Fraunhofer IOF ()
CCD cameras; optical system; wave filters; absorption loss; detection efficiency

A method that significantly increases the detection efficiency of filter array-based spectral sensors is proposed. The basic concept involves a wavelength-dependent redistribution of incident light before it reaches the filter elements located in front of the detector. Due to this redistribution, each filter element of the array receives a spatially concentrated amount of a pre-selected and adjusted spectral partition of the entire incident light. This approach can be employed to significantly reduce the reflection and absorption losses of each filter element. The proof-of-concept is demonstrated by a setup that combines a series of consecutively arranged dichroic filters with Fabry–Perot filter arrays. Experimentally, an efficiency increase by a factor larger than 4 compared to a reference system is demonstrated. The optical system is a non-imaging spectrometer, which combines the efficiency enhancement module with the filter arrays, is compact (17.5 mm × 17.5 mm × 7.8 mm), and integrated completely inside the CCD camera mount.