We investigate the spectral filtering effect on the mid-infrared ultrafast ${{\rm Er}^{3 +}}$-doped ZBLAN fiber laser based on nonlinear polarization evolution (NPE). A broad wavelength tuning range from 2720 nm to 2800 nm is achieved using a diffraction grating as the narrowband filter. Furthermore, numerical simulations are also carried out so that, by inserting a highly nonlinear fiber combined with an appropriate spectral filter in the laser system, a 329 nm ultra-broadband spectrum with a Fourier transform limit pulse as short as 47 fs can be achieved. Our results are conducive to understanding the spectral filtering effect on the lasing performance of mid-infrared ultrafast fiber lasers.

中文翻译：

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超快中红外Er3+掺杂ZBLAN光纤激光器的光谱滤波效应

我们研究了基于非线性偏振演化 (NPE)的中红外超快${{\rm Er}^{3 +}}$掺杂 ZBLAN 光纤激光器的光谱滤波效应。使用衍射光栅作为窄带滤波器实现了从 2720 nm 到 2800 nm 的宽波长调谐范围。此外，还进行了数值模拟，通过在激光系统中插入高度非线性的光纤并结合适当的光谱滤波器，可以实现具有短至 47 fs 的傅立叶变换极限脉冲的 329 nm 超宽带光谱。我们的研究结果有助于理解光谱滤波对中红外超快光纤激光器的激光性能的影响。