A New Method for Phosphorescence Measurements in the Presence of Scattered Light

− Phosphorescent sensors are usually based on measurement of light intensity or lifetime of sensor emitted light. This goal may be accomplished by measuring the phase-shift between the excitation and the emitted light. Scattered signals must be removed to perform the measurement; however, some of the scattered light due to fluorescence is impossible to remove when measuring phosphorescence decay times. In this paper, a new method to measure lifetime in the presence of fluorescence light emitted by the phosphorescence sensor is presented. This method is based on the measurement of the phase-shift at two different frequencies. Theoretical aspects, the optimal frequencies and experimental results are discussed.