Lifetime detection methods time gating

In TG methods, the fluorescence emission is detected in two or more time-gates each delayed by a different time relative to the excitation pulse (see Fig. 3.3). In the case of a detection scheme equipped with two time-gates, the ratio of the signals acquired in the two time-gates is a measure of the fluorescence lifetime. For a decay that exhibits only a single exponent, the fluorescence lifetime is given by ... 

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