Picosecond optical pulses were obtained by fibre compression of chirped pulses from a tunable three-sectional distributed-Bragg-reflector (DBR) diode laser. The linear frequency chirp was imposed by the subnanosecond scan of the emission wavelength. A chirp bandwidth of 4nm, which corresponds to 1 ps of bandwidth-limited pulse duration, was achieved. The measured minimal duration of the compressed pulses was 50 ps and was limited by the response speed of the measurement system.