High-peak power diode-pumped Yb:CaF 2 laser

With the advent of efficient semiconductor high-power lasers, compact diode-pumped solid-state laser systems are becoming an attractive approach for the generation of high-peak intensities. Due to their low quantum defect and a long fluorescence lifetime, ytterbium-doped gain media are preferably used in diode-pumped laser amplifiers with high-average power and high-pulse energy. Furthermore, owing to their broad gain spectrum Ytterbium-doped alkaline-earth fluorides (Yb:CaF 2 , Yb:SrF 2 , Yb:BaF 2 ) are promising gain media for diode-pumped, femtosecond lasers and amplifiers [1,2]. Here, we report on a diode-pumped chirped-pulse amplifier employing Yb:CaF 2 to amplify femtosecond laser pulses to the terawatt level. Cylindrical Yb:CaF 2 crystals with a diameter of 28 mm and a length of 20 mm were used, which were provided by the Institute for Crystal Growth (IKZ), Berlin, Germany, and the Shanghai Institute of Optics and Fine Mechanics (SIOF), Chinese Academy of Sciences.