Gösch, M.Blom, H.Anderegg, S.Korn, K.Thyberg, P.Wells, M.Lasser, T.Rigler, R.Magnusson, A.Hård, S.2006-10-032006-10-032006-10-03200510.1117/1.2080707https://infoscience.epfl.ch/handle/20.500.14299/234924WOS:0002337113000337786Dual-color cross-correlation spectroscopy allows the detection and quantification of labeled biomolecules at ultra-low concentrations, whereby the sensitivity of the assay correlates with the measurement time. We now describe a parallel multifocal dual-color spectroscopic configuration employing multiple avalanche photodiodes and hardware correlators. Cross-correlation curves are obtained from several dual-color excitation foci simultaneously. Multifocal dual-color excitation is achieved by splitting each of two laser beams (488 and 633 nm) into four sub- beams with the help of two 2×2 fan-out diffractive optical elements (DOEs), and subsequent superposition of the two sets of four foci. The fluorescence emission from double- labeled biomolecules is detected by two 2×2 fiber arrays.87.64.Ni87.15.-v42.79.-e85.60.Dw87.80.-ytext::journal::journal article::research article