Full correlation from picoseconds to seconds by time-resolved and time-correlated single photon detection

We present an advanced time-correlated single photon counting (TCSPC) technique that delivers traditional fluorescence correlation (FCS) or cross correlation (FCCS) and fluorescence lifetime data simultaneously. Newly developed electronics allow for detection and registration of single photon events over time periods of hours with picoseconds accuracy. Subsequent software-correlation yields correlation curves covering more than 12 orders of magnitude in time. At the same time, the original data, containing all information accessible by single photon counting techniques, can be analyzed conventionally according to common single molecule fluorescence techniques. Potential applications of the new technique using pulsed or cw laser excitation are discussed.