Hybrid Fiber-Single Crystal Fiber Chirped-Pulse Amplification System Emitting More Than 1.5 GW Peak Power With Beam Quality Better Than 1.3

Abstract

A hybrid chirped pulse amplification system composed by the monolithic fiber pre-amplifier and a two-stage single-pass single crystal fiber amplifier was demonstrated. A maximum power of 68 W at the repetition rate of 100 kHz was obtained. The laser pulses were amplified and then compressed using a 1600 line/mm grating pair compressor. A short pulse duration of 358 fs and a power of 54 W were obtained at 100 kHz, corresponding to a peak power of 1.508 GW, to the best of our knowledge, this is the highest peak power ever obtained from single crystal fiber at repetition rate above 100 kHz due to the consideration of the third order dispersion which was engraved in the stretcher and the tuning capacity of higher-order dispersion compensation of chirped fiber Bragg grating. Additionally, the beam quality better than 1.3 was obtained. This high peak power CPA system with excellent comprehensive parameters will find various applications in scientific research and industrial applications.Index Terms-single crystal fiber; high peak power; chirped pulse amplification; high-order dispersion compensation.N the last decade, ultrafast lasers have found various applications in science and industry, e.g., attosecond generation[1], THz generation[2], ultrafast pump-probe spectroscopy[3], angle resolved photoemission spectroscopy [4], and material precision machining [5][6][7][8]. Most of these femtosecond lasers are configured in chirped pulse amplification architectures. Notable results with kilowatts average power have been reported by different Yb-doped gain mediums, such as the thin-disk amplifier[9], the innoslab amplifier[10] and Yb-doped fibers [11]. The thin-disk and innoslab lasers'inherent complexity and multiple passes of the laser beam with no optical wave guide pose a challenge for