Making self mode locking experiment using the 3 mm Ti:sapphire short rod and the improved asymmetric Z shape folding configuration, with quartz prisms as dispersion compensation element, we achieve low threshold self mode locking operation with 5 W pumping power of Argon laser and soft aperture mode Locking without any modulating element. The pulse duration is 15 fs with 80 nm spectrum bandwidth. The 400 mW average power is obtained.