We investigate the frequency-resolved intensity noise spectrum of an Yb-doped fiber amplifier down to the fundamental limit of quantum noise. We focus on the kHz and low MHz frequency regime with special interest in the region between 1 and 10 kHz. Intensity noise levels up to $$\ge$$ ≥ 60 dB above the shot noise limit are found, revealing great optimization potential. Additionally, two seed lasers with different noise characteristics were amplified, showing that the seed source has a significant impact and should be considered in the design of high power fiber amplifiers.

中文翻译：

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掺镱光纤放大器中强度噪声水平的量子限制测量

我们研究了掺镱光纤放大器的频率分辨强度噪声谱，直到量子噪声的基本极限。我们专注于 kHz 和低 MHz 频率范围，特别关注 1 到 10 kHz 之间的区域。发现强度噪声水平高达 $$\ge$$ ≥ 60 dB 以上的散粒噪声限制，揭示了巨大的优化潜力。此外，放大了两种不同噪声特性的种子激光器，表明种子源具有显着影响，在设计高功率光纤放大器时应予以考虑。