A polymeric minus filter for an incident electromagnetic spectral band comprises at least one polymeric interference stack tuned to a predetermined design wavelength centered around .lambda..sub.0, wherein .lambda..sub.0 is in the range of 300 nm to 2000 nm, said filter comprises an optically transparent...http://www.google.es/patents/US5238738?utm_source=gb-gplus-sharePatente US5238738 - Polymeric minus filter
