396 MHz CPA femtosecond laser system based on a single crystal fiber rod-type amplifier

The paper presents the results of multiplying the repetition frequency of the seed source to 396 MHz using an extra-cavity fiber multiplication method. The single crystal fiber rod-type amplifier was able to boost the average output power to approximately 15.9 W. Using a transmission gratings-based pulse compressor, an average output power of 9.56 W was achieved, corresponding to a burst energy of up to 382 µJ and a compression efficiency of 81.7%. The shortest pulse duration was optimized to be 594 fs; however, an obvious pedestal was also observed. This system reduces the impact of nonlinear effects on the device by increasing the repetition frequency, thereby increasing the injection energy of a single process in industrial processing.