We report on the development of an ultrafast Transmission Electron Microscope based on a laser-driven cold-field emission source. We first describe the instrument before reporting on numerical simulations of the laser-driven electron emission. These simulations predict the temporal and spectral properties of the femtosecond electron pulses generated in our ultrafast electron source. We then discuss the effects that contribute to the spatial, temporal and spectral broadening of these electron pulses during their propagation from the electron source to the sample and finally to the detectors of the electron microscope. The spectro-temporal properties are then characterized in an electron/photon cross-correlation experiment based on the detection of electron energy gains. We finally illustrate the potential of this instrument for ultrafast electron holography and ultrafast electron diffraction.

我们报告了基于激光驱动的冷场发射源的超快速透射电子显微镜的发展。在报告激光驱动电子发射的数值模拟之前，我们首先描述该仪器。这些模拟预测了在我们的超快电子源中产生的飞秒电子脉冲的时间和光谱特性。然后，我们讨论了在这些电子脉冲从电子源传播到样品并最终传播到电子显微镜的检测器期间，这些电子脉冲在空间，时间和光谱上变宽的作用。然后基于电子能量增益的检测，在电子/光子互相关实验中对光谱-时间特性进行表征。