Design, construction and characterisation of a diode-pumped, three-element, 1-GHz Kerr-lens-modelocked Ti:sapphire oscillator

We present a design and construction prescription for a 1-GHz repetition rate Ti:sapphire laser pumped with a single green pump diode and with a resonator comprising as few as three optical elements. In a three-element configuration, the laser produces 111-fs pulses and exhibits self-starting Kerr-lens modelocking at pump powers above 850 mW. At 1.1 W of pump power, the average output of the laser is over 116 mW, and the slope efficiency is measured to be 13%. With the addition of a fourth dispersion-compensating element to optimise the second-order group-delay intracavity dispersion, we have demonstrated a reduction of the pulse durations to 87 fs with an average power of 108 mW.