Development of high average power, femtosecond modelocked Yb:YAG laser

Kosuge, Atsushi  ; Ochi, Yoshihiro; Okada, Hajime; Tanaka, Momoko; Mori, Michiaki; Kiriyama, Hiromitsu; Nagashima, Keisuke

Femtosecond laser source with high average power are attractive tools for industrial and scientific applications and its research and development are done all over the world. The thin disk laser which has a very thin disk gain medium solves the thermal problems occurring in conventional high power rod and slab lasers. In this presentation, we developed a high average power diode-pumped Yb:YAG thin disk oscillator. The thickness of the thin disk gain medium is 200 micrometers and it is mounted directly onto a heat sink and used in reflection. The heat flow is mainly one dimensional towards the heat sink, which significantly reduces thermal problems. We demonstrated the passively mode locked thin disk Yb:YAG laser using a saturable absorber mirror (SESAM) and a second harmonic nonlinear mirror (NLM) technique with a LBO crystal.