[en] We stabilized the pulse timing of a mode-locked Ti:sapphire laser for electron-laser Compton scattering. The short-term jitter was reduced to 77 fs and the long-term drift was reduced to 70 μHz. We achieved the synchronization of two independent mode-locked lasers, and proposed a new method for shingle-shot jitter measurement. (author)

[en] We started to develop a compact high repetition rate and ultrashort pulse femtosecond amplified system for material processing applications. Ti: sapphire crystal in the laser system is cooled to reduce the effects of the thermal lens in the crystal, which cause instability of the laser output. We obtained 7.6 W power in the amplifier with the spectrum width of over 50 nm from the amplifier when pumping green power was 18 W. When the efficiency of the compressor is 55%, we can obtain over 4 W with the pulse duration of sub-25-fs. Our final goal is 2 mJ, 20 fs laser system at 5 kHz (10W) and 1 kHz system is this year's goal (2W). (author)

[en] We started to develop a compact high repetition rate and ultrashort pulse femtosecond amplified system for material processing and scientific applications. Our final goal is 2 mJ, 20 fs laser system at 5 kHz. Ti:sapphire crystal in the laser system is cooled to reduce the focal length of the thermal lens in the crystal, which cause instability of the laser output. We demonstrated 3.8 W output power from the amplifier when pumping green power was 23 W. When the efficiency of the compressor is 55%, we can obtain over 2 W. (author)