Using the SBS phase conjugation and pulse compression technique, a conventional long pulse ruby laser was successfully converted to give 300ps pulses at 1 Joule energy level. The technique allows the use of smaller amplifiers than required in a conventional short pulse laser which in turn leads to operation at increased repetition rate. The completed laser when operated at 1.5Hz produces stable output parameters. Each laser pulse is characterised by a sharp rise and a measured pre-pulse level of less than 10­6 of the main pulse, making it suitable for LIDAR Thomson scattering measurements.