Köttig F, Novoa D, Tani F, Günendi M C, Cassataro M, Travers J C, Russell P St J
Max Planck Institute for the Science of Light, Staudtstrasse 2, 91058, Erlangen, Germany.
School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh, EH14 4AS, UK.
Nat Commun. 2017 Oct 9;8(1):813. doi: 10.1038/s41467-017-00943-4.
Gas-filled hollow-core photonic crystal fibre is being used to generate ever wider supercontinuum spectra, in particular via dispersive wave emission in the deep and vacuum ultraviolet, with a multitude of applications. Dispersive waves are the result of nonlinear transfer of energy from a self-compressed soliton, a process that relies crucially on phase-matching. It was recently predicted that, in the strong-field regime, the additional transient anomalous dispersion introduced by gas ionization would allow phase-matched dispersive wave generation in the mid-infrared-something that is forbidden in the absence of free electrons. Here we report the experimental observation of such mid-infrared dispersive waves, embedded in a 4.7-octave-wide supercontinuum that uniquely reaches simultaneously to the vacuum ultraviolet, with up to 1.7 W of total average power.Dispersive wave emission in gas-filled hollow-core photonic crystal fibres has been possible in the visible and ultraviolet via the optical Kerr effect. Here, Köttig et al. demonstrate dispersive waves generated by an additional transient anomalous dispersion from gas ionization in the mid-infrared.
充气空心光子晶体光纤正被用于产生越来越宽的超连续谱，特别是通过深紫外和真空紫外波段的色散波发射，具有众多应用。色散波是能量从自压缩孤子进行非线性转移的结果，这一过程关键依赖于相位匹配。最近有预测称，在强场 regime 中，气体电离引入的额外瞬态反常色散将允许在中红外波段产生相位匹配的色散波——这在没有自由电子的情况下是被禁止的。在此，我们报告了对这种中红外色散波的实验观测，它嵌入在一个 4.7 倍频程宽的超连续谱中，该超连续谱独特地同时延伸至真空紫外波段，总平均功率高达 1.7 瓦。通过光学克尔效应，在可见和紫外波段实现充气空心光子晶体光纤中的色散波发射已成为可能。在此，科蒂格等人展示了由气体电离产生的额外瞬态反常色散在中红外波段产生的色散波。
