Spatiotemporal optical vortices (STOVs) are a new type of optical orbital angular momentum (OAM) with optical phase circulation in space–time. In prior work [Phys. Rev. X. 6, 031037 (2016) [CrossRef] ], we demonstrated that a STOV is a universal structure emerging from the arrest of self-focusing collapse leading to nonlinear self-guiding in material media. Here, we demonstrate linear generation and propagation in free space of STOV-carrying pulses. Our measurements and simulations demonstrate STOV mediation of space–time energy flow within the pulse and conservation of OAM in space–time. Single-shot amplitude and phase images of STOVs are taken using a new diagnostic, transient grating single-shot supercontinuum spectral interferometry.

中文翻译：

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时空光学涡旋的自由空间传播

时空光学涡旋（STOV）是一种新型的光学轨道角动量（OAM），其时空中具有光学相位循环。在先前的工作中[Phys。启X. 6，031037（2016）[交叉引用] ]，我们表明，一个STOV是一种通用的结构，从自聚焦崩溃导致非线性自引导在材料媒体逮捕出现。在这里，我们演示了在携带STOV的脉冲的自由空间中的线性生成和传播。我们的测量和仿真表明，在脉冲内时空能量流的STOV中介和在时空中OAM的守恒。使用新的诊断，瞬态光栅单次超连续谱干涉仪拍摄STOV的单次振幅和相位图像。