A method and apparatus for using a square wave- or sinewave-driven electroluminescent lamp (ELL) as a source of periodically pulsed excitation light for a luminescent molecule, wherein changes in decay time, phase angle and/or modulation of the emitted luminescence are detected as parameters that correspond...http://www.google.ca/patents/US5281825?utm_source=gb-gplus-sharePatent US5281825 - Phase fluorometry using a modulated electroluminescent lamp as a light source
