High power mode comb from a non-collinear optic parametric oscillator

几十年来，光学参量振荡器（opo）以产生窄带宽、可接受的平均输出功率和宽可调性的飞秒脉冲而闻名。在这个项目中，我们将首次探索新的概念来获得少周期脉冲持续时间。非共线泵浦几何结构允许超宽带增益带宽（我们称之为NOPO）。在第二个焦点中添加基于Kerr的快速饱和吸收器，结合基于双啁啾反射镜的宽带色散管理，可以产生来自OPO的前几个周期脉冲。主要的挑战将是控制腔内脉冲整形动力学，使超谱保持在一个长脉冲中，以获得最大的增益提取；我们的方法是基于在光纤振荡器的背景下精心阐述的思想。与可比的激光振荡器相比，由于没有热透镜效应，这里的输出功率仅受泵浦激光器功率的限制。通过使用自制的基于薄片的飞秒高功率激光器进行抽运，我们将接近平均输出功率的多瓦水平。来自NOPO的稳定脉冲序列形成宽带模式梳状结构，将分别对其相干特性和时序抖动进行深入研究。这种高功率模式梳子的新概念允许有效的频率转换到远波长区域，特别是近紫外线。

For decades optic parametric oscillators (OPOs) are well known for producing femtosecond pulses with narrow bandwidth, acceptable average output powers, and wide tunability. In this project, we will explore novel concepts to access the few‐cycle pulse duration regime for the first time. Non‐collinear pumping geometry allows for ultra broadband gain bandwidth (we then call it NOPO). Adding a Kerr‐based fast saturable absorber in a second focus in combination with double‐chirped mirror based broadband dispersion management gives rise to the first few‐cycle pulses from an OPO. The main challenge will be the control of the intracavity pulse shaping dynamics to keep the ultrabroad spectrum in a long pulse for maximum gain extraction; our approach is based on ideas well elaborated in the context of fiber oscillators. In contrast to comparable laser oscillators, here the output power is only limited by the power of the pump laser due to the absence of thermal lensing effects. By pumping with a home‐built thin‐disk based femtosecond high power laser, we will approach the multi‐Watt level of average output power. The stable pulse train from the NOPO forms a broadband mode comb, which will be subject of in‐depth investigations regarding its coherence properties and timing jitter respectively. This very new concept for high power mode combs allows for efficient frequency conversion into remote wavelength regions, especially the near UV.