Multifarious Two-Photon Fluorescence Microscopy Employing Ultrabroadband Femtosecond Laser Pulses

We demonstrate two-photon excited fluorescence (TPEF) microscopy employing the novel spectral phase modulation, which permits not only the selective excitation but also the simultaneous excitation together with controlling TPEF intensities from various fluorophores freely. The selective excitation is applied to the sequential dual-color imaging without emission crosstalk and FRET imaging of a HeLa cell. By the simultaneous excitation, dual-color imaging with various signal ratios including equal signal ratio is successfully achieved.