Silva de Oliveira Vinicius, Ruehl Axel, Masłowski Piotr, Hartl Ingmar
Opt Lett. 2020 Apr 1;45(7):1914-1917. doi: 10.1364/OL.391195.
We experimentally demonstrate in a difference-frequency generation mid-infrared frequency comb source the effect of temporal overlap between pump and signal pulses on the relative intensity noise (RIN) of the idler pulse. When scanning the temporal delay between our 130 fs long signal and pump pulses, we observe a RIN minimum with a 3 dB width of 20 fs delay and a RIN increase of 20 dB in 40 fs delay at the edges of this minimum. We also demonstrate active long-term stabilization of the mid-infrared frequency comb source to the temporal overlap setting corresponding to the lowest RIN operation point by an online RIN detector and active feedback control of the pump-signal pulse delay. This active stabilization setup allows us to dramatically increase the signal-to-noise ratio of mid-infrared absorption spectra.
我们在一个差频产生中红外频率梳源中通过实验证明了泵浦脉冲和信号脉冲之间的时间重叠对闲频脉冲相对强度噪声（RIN）的影响。当扫描我们130飞秒长的信号脉冲和泵浦脉冲之间的时间延迟时，我们观察到RIN最小值，其3分贝宽度为20飞秒延迟，并且在该最小值边缘处40飞秒延迟时RIN增加20分贝。我们还通过在线RIN探测器以及对泵浦 - 信号脉冲延迟的主动反馈控制，证明了中红外频率梳源能够长期主动稳定到对应于最低RIN工作点的时间重叠设置。这种主动稳定装置使我们能够显著提高中红外吸收光谱的信噪比。
