Abstract

In recent years, laser-diode (LD) pumped solid-state lasers based on Yb³⁺-ions doped gain media have been investigated for high power, highly efficient ultrafast laser sources. Yb³⁺-doped Lu₃Al₅O₁₂ (Yb:LuAG) is one of the favourable gain materials because of its high thermal conductivity even with high Yb³⁺-doping concentration [1]. However, narrow gain badwidth in Yb :LuAG is a large disadvantage for ultrashort pulse generation. Recently, SESAM (Semiconductor saturable absorber)-initiated passive mode-locking of Yb:LuAG ceramics [2-3] and single crysal [4] have been demonstrated. However, all of the demonstrations could not realize high output power with short pulse duration. A Kerr-lens mode-locking (KLM) technique was expected to improve the laser performances due to its deeper modulation depth and lower intra-cavity loss than those of SESAM.

© 2015 IEEE