Nonlinear chirped pulse amplification for a 100-W-class GHz femtosecond all-fiber laser system at 1.5 m
Yiheng Fan, Hao Xiu, Wei Lin, Xuewen Chen, Xu Hu, Wenlong Wang, Junpeng Wen, Hao Tian, Molei Hao, Chiyi Wei, Luyi Wang, Xiaoming Wei, Zhongmin Yang
Abstract
Abstract In this work, we present a high-power, high-repetition-rate, all-fiber femtosecond laser system operating at 1.5 $\unicode{x3bc}$ m. This all-fiber laser system can deliver femtosecond pulses at a fundamental repetition rate of 10.6 GHz with an average output power of 106.4 W – the highest average power reported so far from an all-fiber femtosecond laser at 1.5 $\unicode{x3bc}$ m, to the best of our knowledge. By utilizing the soliton-effect-based pulse compression effect with optimized pre-chirping dispersion, the amplified pulses are compressed to 239 fs in an all-fiber configuration. Empowered by such a high-power ultrafast fiber laser system, we further explore the nonlinear interaction among transverse modes LP 01 , LP 11 and LP 21 that are expected to potentially exist in fiber laser systems using large-mode-area fibers. The intermodal modulational instability is theoretically investigated and subsequently identified in our experiments. Such a high-power all-fiber ultrafast laser without bulky free-space optics is anticipated to be a promising laser source for applications that specifically require compact and robust operation.