论文标题
频率梳子生成阈值$χ^{（2）} $光学微孔子
Frequency comb generation threshold in $χ^{(2)}$ optical microresonators
论文作者
论文摘要
我们研究了$χ^{（2）} $频率梳子在理论上和实验上的频率梳子产生的阈值。当通过第二次谐波生成生成频率梳子时，发现导致梳子的二阶过程的发作的阈值约为85 $μ$ w。直到该值的第二谐波生成效率与先前已知的理论框架非常吻合。此框架在此处扩展，表明级联$χ^{（2）} $过程的发作和第二次谐波发电效率的最大值一致。此外，我们观察到梳子线之间的频率距离是泵功率的函数。它从振荡阈值的4个自由光谱范围变为590 $μ$ w的1个自由光谱范围。
We investigate the threshold of $χ^{(2)}$ frequency comb generation in lithium niobate whispering gallery microresonators theoretically and experimentally. When generating a frequency comb via second-harmonic generation, the threshold for the onset of cascaded second-order processes leading to a comb is found to be approximately 85 $μ$W. The second-harmonic generation efficiency up to this value is in excellent agreement with a previously known theoretical framework. This framework is extended here, showing that the onset of cascaded $χ^{(2)}$ processes and the maximum of the second-harmonic generation efficiency coincide. Furthermore, we observe that the frequency distance between the comb lines is a function of the pump power. It changes from 4 free spectral ranges at the oscillation threshold to 1 free spectral range at 590 $μ$W.
