[19p-E205-1~19] 3.6 超高速・高強度レーザー

[19p-E205-14] 共振器内高次高調波発生用高繰返しYb:YAG 薄ディスクレーザーの969nm励起による高出力化

〇棚橋 晃宏¹、アマニ レザ²、神田 夏輝³、鍋川 康夫¹、五神 真³、緑川 克美^1,3 (1.理研、2.オークランド大、3.東大)

キーワード：高強度レーザー、超短パルス、固体レーザー

For applications such as photoelectron spectroscopy or photo-chemical studies, multi-MHz rate highly coherent XUV sources are demanded. One way of achieving this is intra-cavity High-order Harmonic Generation (HHG) with high power laser oscillator. Yb:YAG thin-disk lasers are very suitable for the pumping of such high repetition rate XUV radiation. We already succeeded in generating HH fields at the University of Tokyo “Photon Ring” facility. To boost the peak power, a new scheme of pumping with 969nm absorption line (i.e. Zero-Phonon-Line) of Yb:YAG which exhibits low quantum defect was tested with RIKEN compact ring. With a fiber coupled 969nm LD pumping, power scaling was succeeded owing to its less wavefront distortion due to the reduction of accumulated heat on the thin-disk. We obtained stable Kerr-Lens-Modelocking at 15MHz operation with the intracavity peak power of 162MW and its pulse energy could result in 5uJ (57uJ, intracavity) with 310fs pulse duration in the ring oscillator.