Parallel fluorescence correlation spectroscopy with a fully integrated single photon 2x2 detector array made with conventional CMOS technology

We present multipoint Fluorescence Correlation Spectroscopy (FCS) experiments with a fully integrated Complementary Metal Oxide Semiconductor (CMOS) single photon 2x2 detector array. Multifocal excitation was achieved with a diffiractive optical element (DOE). Special emphasis was put on parallelization of the total system. In particular the performance of the single-photon CMOS detector was investigated and compared to a state-of-the art single-photon detecting module (actively quenched avalanche photo diode) by measurements on free diffusing molecules at different concentrations. The potential of our new technique for high throughput FCS based systems is discussed.