In 1962 at MIT, together with Louis Smullin, Fiocco developed the first Lidar system, aiming a laser beam to the Moon and detecting the return pulse. Fiocco was full professor of geophysics at the University of Florence, then since 1974, professor of Terrestrial Physics at the Sapienza University of Rome. From 1994 to 1995 Fiocco was president of the Italian Space Agency. Fiocco pioneered the application of the Lidar to the remote sensing of the atmosphere.