Abstract
Synchronously-pumped mode-locked dye lasers are very useful sources of ultrashort pulses because of their wide tuning ranges throughout the visible spectrum and high average power. Moreover pulse shortening to the femtosecond regime is now possible by utilising the nonlinear properties of optical fibre [1], giving pulse durations which approach the shortest which have been achieved from passively mode- locked dye lasers. However with synchronous pumping the structure and stability of the dye laser pulses depend critically on the quality of mode-locking of the pump (cw Nd:YAG or ion laser).