In the present work, we report a path of RF stabilization versus delay subject to self-mode-locked (SML) two-section quantum-dash (QDash) lasers emitting at ∼1.55 μm and operating at ∼21 GHz repetition rate using a feedback ratio controlled and optical delay phase-dependent symmetric dual-loop optical feedback. For symmetric dual-loops (equal arms of external loops), we identify the three key parameters: power-split ratio through each cavity of the external feedback loop, optical delay phase settings, and overall feedback strength back into gain section, yields jitter stabilization on integer resonance as well as on full delay range tuning. Symmetric dual-loop feedback with two optical delay phase settings (weaker cavity set to integer resonance, fine-tuning of the stronger cavity and stronger cavity set to integer resonance, fine-tuning of a weaker cavity) and four chosen combinations of feedback ratios (−19.5:−29.03 dB, −20.6:−24.3 dB, −21:−22.7 dB, −21.3:−23 dB) has been demonstrated. Based on these four chosen combinations of feedback ratios and optical delay phase settings, a path of stabilization has been identified for SML QDash lasers using symmetric dual-loop optical feedback. Our proposed dual-loop feedback schemes provide a viable path towards the stabilization of mode-locked lasers, promising for various practical applications where ultra-stable optical pulses are highly desirable.

中文翻译：

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双环光反馈下功率分流比和光延迟相位调谐对自锁模量子破折号激光器稳定性的影响

在目前的工作中，我们报告了受自锁模 (SML) 两段量子破折号 (QDash) 激光器影响的 RF 稳定性与延迟的路径，该激光器以 ~1.55 μm 发射并使用反馈以 ~21 GHz 重复率运行比率控制和光延迟相位相关的对称双回路光反馈。对于对称双环路（外部环路的等臂），我们确定了三个关键参数：通过外部反馈环路每个腔的功率分配比、光延迟相位设置和返回增益部分的整体反馈强度，产生抖动稳定性整数谐振以及全延迟范围调谐。具有两个光学延迟相位设置的对称双回路反馈（较弱的腔设置为整数谐振，微调较强的腔和较强的腔设置为整数谐振，微调较弱的腔）和四种选择的反馈比组合（-19.5:-29.03 dB、-20.6:-24.3 dB、-21:-22.7 dB、-21.3:-23 dB）已被证明。基于这四种选择的反馈比和光学延迟相位设置组合，使用对称双回路光学反馈为 SML QDash 激光器确定了稳定路径。我们提出的双回路反馈方案为稳定锁模激光器提供了一条可行的途径，有望用于需要超稳定光脉冲的各种实际应用。使用对称双回路光学反馈为 SML QDash 激光器确定了一条稳定路径。我们提出的双回路反馈方案为稳定锁模激光器提供了一条可行的途径，有望用于需要超稳定光脉冲的各种实际应用。使用对称双回路光学反馈为 SML QDash 激光器确定了一条稳定路径。我们提出的双回路反馈方案为稳定锁模激光器提供了一条可行的途径，有望用于需要超稳定光脉冲的各种实际应用。