  We present a dual color laser scanning endomicroscope capable of fluorescence
lifetime endomicroscopy at one frame per second (FPS). The scanning system uses
a coherent imaging fiber with 30,000 cores. High-speed lifetime imaging is
achieved by distributing the signal over an array of 1024 parallel
single-photon avalanche photo--diode detectors (SPADs), minimizing detection
dead time maximizing the number of photons detected per excitation pulse
without photon pile--up to achieve the high frame rate. Dual color fluorescence
imaging is achieved by temporally shifting the dual excitation lasers, with
respect to each other, to separate the two spectrally distinct fluorescent
decays. Combining the temporal encoding, to provide spectral separation, with
lifetime measurements we show a one FPS, multi-channel endomicroscopy platform
for clinical applications and diagnosis. We demonstrate the potential of the
system by imaging smartprobe-labeled bacteria in ex vivo samples of human lung
using lifetime to differentiate bacterial fluorescence from the strong
background lung auto--fluorescence which was used to provide structural
information.
