AbstractLight detection and ranging (LIDAR) Thomson scattering is an effective method for measuring electron temperature and density in magnetic confinement plasma devices. The LIDAR system requires a high output energy and a high repetition rate for the light source. We built a small alexandrite system for a feasibility study of the light source. This system includes a laser diode as a short pulse light source to be amplified, an alexandrite laser regenerative amplifier as a preamplifier and the following two-stage double-pass power amplifiers. With this system, we have obtained an output energy of 60 mJ with a pulse width of 320 ps at a repetition rate of 10 Hz.