A simple technique to convert a commercial dye laser into a tunable source of subnanosecond (≤300 ps) pulses with a linewidth of ∼10 GHz (0.01 nm) is described. The technique used is a combination of stimulated Brillouin scattering and optical breakdown. The effectiveness of the system as a spectroscopic tool was demonstrated by using it to record a partial absorption spectrum of iodine.