High-energy pulsed lasers in the green spectral region are of tremendous interest for applications in space laser ranging, underwater detection, precise processing, and scientific research. Semiconductor pulsed lasers currently are difficult to access to the so-called “green gap,” and high-energy green pulsed lasers still heavily rely on the nonlinear frequency conversion of near-IR lasers, precluding compact and low-cost green laser systems. Here, we address this challenge by demonstrating, for the first time to the best of our knowledge, millijoule-level green pulses generated directly from a fiber laser. The green pulsed fiber laser consists of a 450 nm pump laser diode, a Ho3+-doped ZBLAN fiber, and a cavity-dumping module based on a visible wavelength acousto-optic modulator. Stable pulse operation in the cavity-dumping regime at 543 nm is observed with a tunable repetition rate in a large range of 100 Hz–3 MHz and a pulse duration of 72–116 ns. The maximum pulse energy of 3.17 mJ at 100 Hz is successfully achieved, which is three orders of magnitude higher than those of the rare-earth-doped fiber green lasers previously reported. This work provides a model for compact, high-efficiency, and high-energy visible fiber pulsed lasers.

利用正交试验探讨了放电等离子技术工艺参数（温度、压力、保温时间）对钡-钨（Ba-W）阴极中的W的孔隙度的影响规律，获得了孔隙率在23%～30%内变化时所需要的最佳工艺参数。在此基础上，制备出了具有不同孔隙度的球形W基体和普通不规则的W基体。研究表明：球形多孔W颗粒间堆积、排列有序，无闭孔，孔径分布集中而均匀，在26.3%的孔隙度下中值孔径为1.41 μm；机械性能方面，球形钨粉基体维氏硬度低于传统普通不规则钨多孔体。在脉宽10 μs、频率1000 Hz的条件下，阴极脉冲发射电流密度随着孔隙度的增大，先增大后减小。当基体孔隙度为26.3%时，阴极电流发射密度最大，在1050 ℃，偏离点发射电流密度可达24.62 A/cm²，零场发射电流密度为7.62 A/cm²，功函数为1.95 eV。