For many years, TCSPC FLIM has been performed with 256 time channels and a time-channel width on the order of 50 ps. With the introduction of faster detectors the number of time channels was increased to 1024 and the channel width decreased to 10 ps. Recently, bh have introduced detectors with sub-20 ps IRF width. The Nyquist criterion suggests that FLIM data with these detectors should be recorded with a channel width of about 2 ps. To extract ultra-fast decay components hidden in the detector response even smaller time-channel width can be useful. Here, we report on extracting ultra-fast decay components from FLIM data recorded with a time-channel width of 300 femtoseconds. We show that the components of triple-exponential decay decay functions are reliably resolved down to component lifettime of less than 10ps.
Keywords: FLIM, TCSPC, IRF, Ultra-Fast Fluorescence Decay