设计了一种基于半导体激光器调制技术的978 nm纳秒脉冲掺镱全光纤激光器。该激光器采用主振荡功率放大结构，由调制半导体激光种子源和一级单模单包层掺镱光纤放大器组成。半导体激光种子源的光谱中心波长通过种子光自注入方式被定义为978.3 nm，调制之后的激光脉冲宽度为4.5 ns，重复频率在10~50 MHz范围内可调。当半导体激光种子源调制重复频率为50 MHz时，种子光被一级单包层掺镱光纤放大器放大至115 mW，相应的激光中心波长为978.3 nm，3 dB光谱带宽为0.11 nm，放大之后光谱中没有出现明显的放大自发辐射现象。

Based on diode laser modulation technique, a 978 nm nanosecond-pulsed Yb-doped fiber laser is designed. The structure of the laser is master oscillator power amplifier. The laser system consists of the seed of modulated laser diode and one stage Yb-doped fiber amplifier with single-mode and single-cladding. The spectral central wavelength of laser diode seed is set as 978.3 nm by self-seeding. The laser pulse width after modulation is 4.5 ns and the repetition frequency is tunable at 10~50 MHz. The seed light is amplified to 115 mW by one stage Yb-doped fiber amplifier with single-cladding when the repetition frequency of laser diode seed modulation is 50 MHz. The corresponding central wavelength of the laser is 978.3 nm, 3 dB spectral bandwidth is 0.11 nm. The obvious amplified spontaneous emission does not appear in the spectrum after amplification.