Combined scanning optical coherence and two-photon-excited fluorescence microscopy

We demonstrate simultaneous imaging by optical coherence microscopy (OCM) and two-photon-exerted (TPE) fluorescence microscopy. A mode-locked Ti:sapphire laser is focused and scanned in three dimensions through a fixed sample, generating both backscattered light and fluorescence light, which are independently detected. Both imaging modes provide rapid en-face imaging with submicrometer resolution. High-power delivery into the sample yields an OCM sensitivity in excess of 130 dB at 100-kHz pixel rates. Simultaneous imaging of cell nuclei with OCM and TPE is demonstrated in live drosophila embryos. (C) 1999 Optical Society of America OCIS codes: 180.6900, 170.4500, 180.5810, 180.2520, 170.3880, 190.4180.