Hänninen, P. E.P. E.HänninenSoini, E.E.SoiniHell, S. W.S. W.Hell2018-04-232018-04-231994https://resolver.sub.uni-goettingen.de/purl?gro-2/13520Two‐photon excitation fluorescence imaging is feasible with continuous wave lasers. Images of biological specimens are obtained by employing photon counting in conjunction with an increased recording time. The approach allows two‐photon three‐dimensional imaging of fluorescently labelled specimens with inexpensive lasers.enjournal_article10.1111/j.1365-2818.1994.tb03518.x3142380