Patent ID: 7375803

Claim:
For use in a sensor system having a first plurality of detectors responsive to a broad first range of wavelengths dividable into at least a first sub-range and a second sub-range, and having a second plurality of detectors responsive to a narrower second range of longer wavelengths, said first plurality of detectors and said second plurality of detectors sharing a common optical path, a method of filtering incoming optical energy falling upon said sensor system comprising: (a) inputting said incoming optical energy to an interference filter disposed in said common optical path, said interference filter having a broad first pass band passing at least said first range of wavelengths, and having a more sharply defined second pass band that defines said second narrower range of longer wavelengths; (b) subjecting optical energy exiting said interference filter as input to at least a first dye filter having a band pass defining said first sub-range, and as input to a second dye filter having a band pass defining said second sub-range, and as input to a third dye filter having a band pass encompassing said sharply defined second pass band; said first dye filter disposed above at least one detector in said first plurality of detectors responsive to said first sub-range, said second dye filter disposed above at least one detector in said first plurality of detectors responsive to said second sub-range, and said third dye filter disposed above at least one detector in said second plurality of detectors; wherein detectors in said first sub-range, detectors in said second sub-range, and detectors in said second range of longer wavelengths each receive optical energy having wavelengths defined by an intersection of a band pass of a respective dye filter and a band pass of said interference filter.