Fan G, Safaei R, Kwon O, Schuster V, Légaré K, Lassonde P, Ehteshami A, Arias L, Laramée A, Beaudoin-Bertrand J, Limpert J, Tao Z, Spanner M, Schmidt B E, Ibrahim H, Baltuška A, Légaré F
Opt Lett. 2020 Jun 1;45(11):3013-3016. doi: 10.1364/OL.387037.
We demonstrate an efficient approach for enhancing the spectral broadening of long laser pulses and for efficient frequency redshifting by exploiting the intrinsic temporal properties of molecular alignment inside a gas-filled hollow-core fiber (HCF). We find that laser-induced alignment with durations comparable to the characteristic rotational time scale enhances the efficiency of redshifted spectral broadening compared to noble gases. The applicability of this approach to Yb lasers with (few hundred femtoseconds) long pulse duration is illustrated, for which efficient broadening based on conventional Kerr nonlinearity is challenging to achieve. Furthermore, this approach proposes a practical solution for high energy broadband long-wavelength light sources, and it is attractive for many strong field applications.
我们展示了一种有效的方法，通过利用充气空心光纤（HCF）内部分子取向的固有时间特性，来增强长激光脉冲的光谱展宽并实现有效的频率红移。我们发现，与稀有气体相比，持续时间与特征旋转时间尺度相当的激光诱导取向提高了红移光谱展宽的效率。说明了这种方法对于脉冲持续时间为几百飞秒的镱激光器的适用性，而基于传统克尔非线性实现有效的展宽具有挑战性。此外，这种方法为高能宽带长波长光源提出了一种切实可行的解决方案，并且对许多强场应用具有吸引力。
