First Sensor AG
Wavelength-sensitive photodiodes from First Sensor utilize the effect of the wavelength-specific absorption depth of radiation in silicon. For this purpose, two p-n junctions are aligned vertically in the silicon crystal, thus enabling separate signal detection within vertically adjacent ranges. Such a configuration is particularly useful for the wavelength detection of monochromatic input signals. The calculation then merely requires the formation of a quotient between two photocurrents. The calculation of a color temperature from a non-monochromatic input signal requires two such detectors and an additional optical filter.