1GHz,48.8fs高重复频率掺镱光纤飞秒激光器研究

Study on 1GHz repetition rate,48.8fs Yb-doped femtosecond fiber laser

GHz基本重复频率光纤超短脉冲激光器由于具有宽光谱,窄脉宽等优势,在高速光刻,高端制造,天文探测,太赫兹检测,精密仪器等领域应用广泛。然而在实现1GHz以上基本重复频率锁模的前提下,如何输出脉冲宽度在50fs以下的超短脉冲是当前科学研究的难点。文章以实现更宽光谱,更窄脉宽的GHz重复频率光纤超短脉冲激光器为目标,通过非线性偏振旋转锁模(NPR)技术,利用波分复用光纤准直器(WDM-Collimator)缩短激光谐振腔长度,最终实现了48.8fs脉冲宽度的1GHz基本重复频率光纤激光器。该脉冲宽度是当前国际上1μm波段GHz基本重复频率光纤激光器的最窄直接输出脉冲宽度。最后对激光器集成形成样机,并有效降低制造成本,提升了系统稳定性。该激光样机可满足天文光梳、卫星导航等领域空间尺寸的需求,有望推动高重复频率光纤超短脉冲激光器工业化、商业化发展。

Ultrashort fiber lasers with GHz repetition rate have already demonstrated their applications in laser communication,advanced manufacturing,astronomical and THz detection,et al,due to their advantages of large number of pulses per unit time,wide spectral coverage and narrow pulse duration.However,the main difficulty is how to yield pulses with duration less than 50fs and above 1GHz repetition rate at the same time.A 1.003GHz repetition rate Yb-doped fiber laser was built with 48.8fs pulse duration by using nonlinear polarization rotation mode locking(NPR).In our approach,WDM-Collimator was employed in order to shorten the length of the cavity.This fiber laser had the shortest output pulse duration among all reported Yb-doped fiber lasers with fundamental repetition rate above 1GHz.Finally,the laser was integrated into a prototype,which effectively reduced the manufacturing cost and improved the stability.The laser is expected to promote the industrialization and commercialization of high repetition rate fiber ultrashort pulse lasers.