title: High average power coherent vuv generation at 10 MHz repetition frequency by intracavity high harmonic generation.
abstract: Intracavity high harmonic generation was utilized to generate high average-power coherent radiation at vacuum ultraviolet (vuv) wavelengths. A ytterbium-doped fiber-laser based master-oscillator power-amplifier (MOPA) system with a 10 MHz repetition frequency was developed and used as a driving laser for an external cavity. A series of odd-order harmonic radiations was generated extending down to ∼ 30 nm (41 eV in photon energy). The 7th harmonic radiation generated was centered at 149 nm and had an average output power of up to 0.5 mW. In this way, we developed a sub-mW coherent vuv-laser with a 10 MHz repetition frequency, which, if used as an excitation laser source for photo-electron spectroscopy, could improve the signal count-rate without deterioration of the spectral-resolution caused by space-charge effects.
authors.forename: Akira
authors.initials: A
authors.lastname: Ozawa
authors.forename: Zhigang
authors.initials: Z
authors.lastname: Zhao
authors.forename: Makoto
authors.initials: M
authors.lastname: Kuwata-Gonokami
authors.forename: Yohei
authors.initials: Y
authors.lastname: Kobayashi