The bidirectional mode-locked oscillator is an emerging light source architecture suitable for dual-comb applications. Therein, bidirectional mode-locked fiber lasers (MLFLs) are particularly promising for their cost effectiveness, system compactness, and environmental robustness. However, the pulse energy has been limited to tens of picojoules, restricting practical dual-comb applications, especially in the nonlinear regime. In this paper, we break the pulse energy limit by devising the first bidirectional all-normal dispersion MLFL with an artificial saturable absorber (ASA). Bidirectional dissipative solitons are generated with ${\gt}{{5}}$-THz bandwidths and ${\gt}{{1}}$-nJ pulse energies. Free-running laser performance is extensively characterized, and the physical mechanism for bidirectional ASA mode-locking is studied. Last but not least, a proof-of-concept dual-comb spectroscopy measurement is demonstrated. Our work paves the way for a new class of bidirectional MLFLs benefiting dual-comb applications in both linear and nonlinear regimes.

中文翻译：

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双向锁模全法向色散光纤激光器

双向锁模振荡器是一种新兴的光源架构，适用于双梳状应用。其中，双向锁模光纤激光器（MLFL）因其成本效益，系统紧凑性和环境稳健性而特别有前途。但是，脉冲能量已限制在几十皮焦耳，限制了实际的双梳应用，尤其是在非线性状态下。在本文中，我们通过使用人工可饱和吸收器（ASA）设计了第一个双向全正态色散MLFL，打破了脉冲能量限制。双向耗散孤子的生成是使用$ {\ gt} {{5}} $ -THz带宽和$ {\ gt} {{1}} $-nJ脉冲能量。自由运行的激光性能被广泛表征，并研究了双向ASA锁模的物理机制。最后但并非最不重要的一点是，证明了概念验证的双梳状光谱测量法。我们的工作为新型双向MLFL铺平了道路，该线性MLFL可以在线性和非线性范围内使双梳状应用受益。