GaInP-650 nm self-pulsing laser diodes for fluorescence lifetime measurements

The paper presents the use of self-pulsing GaInP laser diodes for use as excitation sources in fluorescence lifetime measurements. By adjusting the pulse frequency and obtaining the peak-to-trough ratio of the fluorescence intensity a lifetime can be measured. The authors have chosen to work with the GaInP material system which can generate optical wavelengths in the region 630-650 nm making them useful for exciting dyes that are used in biological applications (for example, the DRAQ series of dyes, Nile Blue and Cyanine 5 all have an absorption peak at 630 nm).