色散管理掺铥光纤激光器高能量脉冲的产生

Generation of high-energy pulses in dispersion-managed Tm-doped fiber laser

设计了一种基于色散管理的掺铥光纤激光器。通过调节泵浦功率以及腔内偏振态,首先实现了稳定的展宽脉冲输出,中心波长和脉冲宽度分别为1 939.4 nm和482 fs。最大输出功率为15 mW,对应的单脉冲能量为0.52 nJ。增加泵浦功率到645 mW时,通过适当调节偏振控制器可以实现类噪声脉冲锁模,中心波长为1 940.1 nm。所实现的锁模脉冲具有飞秒量级的尖峰以及皮秒量级的基底。最大输出功率为20.4 mW,相对应的单脉冲能量为0.7 nJ。相比于传统孤子,采用色散管理所实现的锁模脉冲具有更高的脉冲能量。此外,所设计的掺铥光纤激光器可作为理想的主振荡功率放大以及啁啾脉冲放大结构的种子源,进一步提高脉冲能量,拓展2 μm高能光纤激光器的实际应用。

An dispersion-managed thulium(Tm)-doped fiber laser was designed and demonstrated. By adjusting the pump power and the intracavity polarization state, the stable stretched-pulse can be firstly achieved. The center wavelength of stretched-pulse is 1 939.4 nm and the pulse width is 482 fs. The maximum output power of stretched-pulse is 15 mW, and the corresponding single pulse energy is 0.52 nJ. When increasing the pump power to 645 mW, the noise-like pulse can be realized with appropriately adjusting the polarization controller, and the center wavelength is 1 940.1 nm. The mode-locked pulse achieved has femtosecond(fs)-order spike and picosecond(ps)-order pedestal. The maximum output power of noise-like pulse is 20.4 mW and the corresponding single pulse energy is 0.7 nJ. Compared to traditional soliton, the mode-locked pulses achieved under dispersion management have higher pulse energy. In addition, the designed Tm-doped fiber laser can be used as the seed source of the main oscillation power amplification and chirped-pulse amplification structure for improving the pulse energy and further expanding the practical applications of the 2 μm high energy fiber laser.