基于多通单元的高能量耗散孤子锁模光纤振荡器

High energy dissipative soliton mode-locked fiber oscillator based on a multipass cell

为了在有限抽运功率条件下探索基于大模场面积光子晶体光纤的耗散孤子锁模振荡器的能量提升潜力,本文利用多通单元将基于掺镱大模场面积光子晶体光纤锁模振荡器的腔长延展,消除了有限抽运功率的限制,使得该系统能够在较低平均功率水平下获得更高的单脉冲能量.实验上构建了重复频率低至15.58MHz的高能量光子晶体光纤锁模脉冲振荡器,并通过分别使用6nm带宽和12nm带宽的两种不同带宽的光谱滤光片,能够直接输出平均功率分别为3.73W和4.9W的啁啾脉冲,对应单脉冲能量分别为239nJ和314nJ.经过光栅对去啁啾后,最窄脉冲宽度分别为56fs和75fs,对应峰值功率均超过3MW.

To investigate the energy scaling level of large-mode-area photonic crystal fiber-based dissipative soliton mode-locked fiber os- cillators under limited pump power, a multipass cell is inserted in the cavity to lower the repetition rate of the system, and thus higher single energy level can be mapped under the same average power level. High energy mode-locked fiber lasers based on two spectral filters with different bandwidths are demonstrated both working in the all-normal dispersion regime at a repetition rate of 15.58 MHz. Employment of filters with FWHMs of 6nm and 12 nm can achieve stable mode-locked pulses with average powers of 3.73 W and 4.9 W, corresponding to single pulse energies as high as 239 nJ and 314 n J, respectively. The FWHM durations of the dechirped pulses by a transmission grating pair can reach 56 fs and 75 fs, which can generate pulses with peak powers exceeding 3MW in both cases.