We experimentally measure the photoelectron momentum distributions of Ar atoms using two-color 800nm (ω) + 400nm (2ω) counter-rotating circularly polarized fields. By employing a weak fundamental circularly polarized field at 800nm, the atomic potential barrier formed by the strong second harmonic field at 400nm can be modulated. This introduces a spatially rotating temporal two-slit interferometry between the photoelectron wave packets tunneling from the modified barriers in the consecutive cycles. The modulation of the barrier would leave its imprint on the photoelectron interference pattern. In analogy to the analysis of the traditional optical interferometry, we perform the Fourier transform on the photoelectron interference. The modulation on the amplitude and phase of the electron wave packets induced by the weak fundamental field is retrieved.

我们使用双色 800nm ( ω ) + 400nm (2 ω) 反向旋转圆极化场。通过在 800nm 处采用弱基波圆极化场，可以调制由 400nm 处强二次谐波场形成的原子势垒。这在连续循环中从修改后的势垒隧穿的光电子波包之间引入了空间旋转时间双缝干涉测量法。势垒的调制会在光电子干涉图案上留下印记。类似于传统光学干涉测量的分析，我们对光电子干涉进行傅里叶变换。检索了弱基场引起的电子波包的幅度和相位调制。