发表机构
Indian Institute of Science（印度科学研究所）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
该研究通过实验揭示了种子拓扑、功率等四个参数对高功率CW掺镱光纤激光器RF分辨RIN的调控规律，发现单向环形种子MOPA可实现宽带泵浦-RIN抑制，为相关光子学应用提供了设计规则。
AI 中文摘要
据我们所知，本文首次报道了对四个实用设计参数——种子谐振腔拓扑、种子功率、放大器泵浦几何以及种子谐振腔自由光谱范围（FSR）——如何共同塑造高功率连续波（CW）掺镱光纤激光器的射频（RF）分辨相对强度噪声（RIN）进行的可控、对等实验映射。我们对比了独立双向光纤布拉格光栅（FBG）振荡器、FBG种子的主振荡功率放大器（MOPA），以及种子谐振腔FSR约为11.5 MHz和5 MHz的单向环形种子MOPA，所有器件均工作在1064 nm附近，输出功率为72 W，RIN测量范围为10 kHz至1 GHz。在所有设置下，低频RIN受技术噪声限制，几乎与架构无关；而160 kHz以上的RIN由种子谐振腔拓扑及其在放大器中的传输决定。较高的种子功率可抑制中高频RIN，但种子输出与放大输出的对比显示两种拓扑的传输特性相反：对于FBG种子，2 MHz-1 GHz的均方根（RMS）RIN在放大过程中升高（种子功率15 W时，从3.66%升至4.14%）；对于环形种子，该频段的RMS RIN则降低（从1.47%降至1.35%）。前向泵浦可实现最佳的功率缩放/噪声权衡，而将环形FSR从约11.5 MHz降至5 MHz仍保留了高频RIN优势，证实该优势并非模式间距效应。在匹配条件下，环形种子可将160 kHz-2 MHz频段的积分RMS RIN降低2-3倍，2 MHz-1 GHz频段的积分RMS RIN降低约3倍（从约9-10 dB降至近-127.4 dBc/Hz）。这些结果得出了与各频段主导调控参数相关的频段分辨设计规则，因此单向环形种子MOPA为非线性和频率转换光子学提供了一种简单、可扩展的宽带泵浦-RIN抑制途径。
英文摘要
We report, to the best of our knowledge, the first controlled, like-for-like experimental mapping of how four practical design parameters--seed-cavity topology, seed power, amplifier pumping geometry, and seed-cavity free spectral range (FSR)--jointly shape the radio-frequency (RF)-resolved relative intensity noise (RIN) of high-power continuous-wave (CW) Yb-doped fiber lasers. We compare a standalone bidirectional fiber Bragg grating (FBG) oscillator, an FBG-seeded master-oscillator power amplifier (MOPA), and unidirectional ring-seeded MOPAs with FSRs of approximately 11.5 and 5 MHz, all near 1064 nm at a common 72 W output, with RIN measured from 10 kHz to 1 GHz. Across all settings, the low-frequency RIN is technical-noise limited and nearly architecture-independent, whereas RIN above 160 kHz is governed by the seed-cavity topology and its transfer through the amplifier. Higher seed power suppresses the mid- and high-frequency RIN, but the seed-alone and amplified-output comparison reveals opposite transfer for the two topologies: for FBG seeding the 2 MHz-1 GHz RMS RIN increases through amplification (3.66 percent to 4.14 percent at 15 W seed), whereas for ring seeding it decreases (1.47 percent to 1.35 percent). Forward pumping gives the best power-scaling/noise trade-off, while reducing the ring FSR from approximately 11.5 to 5 MHz preserves the high-frequency RIN advantage, confirming it is not a mode-spacing effect. At matched conditions, ring seeding lowers the integrated RMS RIN by 2-3 times (160 kHz-2 MHz) and approximately 3 times (2 MHz-1 GHz, approximately 9-10 dB to near -127.4 dBc/Hz). These results yield band-resolved design rules linking each band to its dominant lever. The unidirectional ring-seeded MOPA thus offers a simple, scalable route to broadband pump-RIN suppression for nonlinear and frequency-conversion photonics.
CommentsSubmitted to IEEE/Optica Journal of Lightwave Technology. 12 pages, 8 figures
