PHASE-MODULATION FLUOROMETER AND METHOD FOR MEASURING NANOSECOND LIFETIMES USING A LOCK-IN AMPLIFIER

摘要

A low cost apparatus and method for measuring nanosecond luminescence lifetimes with a modulated LED light source (44) that is driven by a lock-in amplifier (40). The lock-in amplifier provides both a DC bias and an AC signal used to modulate the intensity of an LED source light at a wavelength capable of exciting a photoluminescent species. The corresponding emission is measured by a PMT with the resulting signal being sent through a DC block back to the lock-in amplifier with no external signal processing or heterodyning required.