Sub-Nanosecond Pulsed LEDs

PLS 265 to 600

NATA in water

10 µM NATA (N-acetyl-L-tryptophanamide) dissolved in water and excited with the PLS 280, driven by the PDL 800-B driver at 2.5 MHz repetition rate using the FluoTime 200. The fluorescence emission at 350 nm was detected by the PMA-185 detector through an f/3.2 monochromator set to 16 nm bandpass. The detector pulses were processed by the TimeHarp 200 TCSPC board. 1.3 million counts were collected within 60 seconds, corresponding to an average detection rate of 21.7 kHz, i.e. less than 1% of the excitation rate thereby avoiding pulse pileup effects. The measured instrument response function (IRF) has a FWHM of 700 ps. The picture below shows the IRF (red), the decay (blue) and the fitted single exponential curve (black). The fitted lifetime is 2.88 ns and the reduced chi-square = 1.065. The quality of the results can be also judged by the residual distribution plotted at the bottom.