Mt. Etna, in Italy, is one of the most active volcanoes in the world. Explosive eruptions produce high columns that, sometimes, may exceed the troposphere with volcanic ash reaching long distances from the summit craters. Damages caused from volcanic ash, mainly to aviation operations, are in fact well-known and the associate hazard can be reduced only with a reliable estimation of volcanic ash concentration. Since 2013, Lidar measurements are routinely carried out with a new portable Raman scanning Lidar system, named AMPLE, mainly used to monitor explosive activity. The AMPLE is a multi-wavelength system able to perform 3D maps of particle optical and microphysical properties. The laser source is a doubled and tripled diode pumped Nd:YAG laser, with a repetition rate of 1KHz. Each signal is acquired with a raw spatial resolution of 30m. The Lidar is operated at Serra La Nave, only 7 km away far from the Etna summits, and, during the winter seasons, at the INAF-Astrophysical Observatory in Catania. The system has been successfully used to detect volcanic aerosol during several Etna explosive events measuring, in some cases, the LR values with greater precision. Estimations of volcanic ash concentration from Lidar measurements allow also to define the regions that should be interdicted to aviation operations. Furthermore, the capability to discriminate spherical and non-spherical particles highlighted marked differences among emissions coming from different Etna summit craters. Lidar measurements here presented show new insights on the plume dispersal during Etna lava fountain events.