We experimentally study the femtosecond supercontinuum (SC) generation using an optical vortex (OV) beam in water. It is demonstrated that the topological charge of the OV beam has little influence on spectral broadening induced by filament, while it has strong influence on spectral intensity. Despite the SC induced by filamentation of optical vortices in air possesses orbital angular momentums (OAMs), the SC generated in water and sapphire loses OAM. However, the light at central wavelength possesses OAMs after filamentation in transparent Kerr media. This study is helpful to the understanding of the physical mechanism of femtosecond SC generation by optical vortices in water.

我们在水中使用光学涡旋 (OV) 光束通过实验研究飞秒超连续谱 (SC) 的生成。结果表明，OV光束的拓扑电荷对灯丝引起的光谱展宽影响不大，而对光谱强度影响很大。尽管由空气中的光学涡流成丝引起的 SC 具有轨道角动量 (OAM)，但在水和蓝宝石中产生的 SC 失去了 OAM。然而，中心波长的光在透明克尔介质中成丝后具有 OAM。该研究有助于理解水中光学涡旋产生飞秒SC的物理机制。