Tailoring electron vortex beams with customizable intensity patterns by electron diffraction holography
用电子衍射全息术定制具有可定制强度图案的电子涡旋束
電子回折ホログラフィーを用いたカスタマイズ可能な強度パターンを有する電子渦ビームのカスタマイズ
전자연사 전식술로 맞춤형 강도 도안을 갖춘 전자와선 빔을 맞춤 제작하다
Haz de vórtice de electrones con patrones de intensidad personalizables personalizados con una Holografía de difracción electrónica
Faisceau de Vortex d'électrons personnalisé avec motif d'intensité personnalisable avec holographie de diffraction d'électrons
Настройка электронного вихревого пучка с настраиваемой прочностью с помощью электронной дифракционной голографии
Pengcheng Huo 霍鹏程 ¹, Ruixuan Yu 于睿儇 ¹, Mingze Liu 刘明泽 ¹, Hui Zhang 张辉 ¹, Yan-qing Lu 陆延青 ¹ ², Ting Xu 徐挺 ¹ ²
¹ National Laboratory of Solid-State Microstructures and Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
中国南京 南京大学 固体微结构物理国家重点实验室 人工微结构科学与技术协同创新中心
² College of Engineering and Applied Sciences, Key Laboratory of Intelligent Optical Sensing and Manipulation and Jiangsu Key Laboratory of Artificial Functional Materials, Nanjing University, Nanjing 210093, China
中国 南京 南京大学现代工程与应用科学学院 智能光传感与调控技术教育部重点实验室 江苏省人工功能材料重点实验室
An electron vortex beam (EVB) carrying orbital angular momentum (OAM) plays a key role in a series of fundamental scientific researches, such as chiral energy-loss spectroscopy and magnetic dichroism spectroscopy. So far, almost all the experimentally created EVBs manifest isotropic doughnut intensity patterns.
Here, based on the correlation between local divergence angle of electron beam and phase gradient along azimuthal direction, we show that free electrons can be tailored to EVBs with customizable intensity patterns independent of the carried OAM. As proof-of-concept, by using computer generated hologram and designing phase masks to shape the incident free electrons in the transmission electron microscope, three structured EVBs carrying identical OAM are tailored to exhibit completely different intensity patterns.
Furthermore, through the modal decomposition, we quantitatively investigate their OAM spectral distributions and reveal that structured EVBs present a superposition of a series of different eigenstates induced by the locally varied geometries. These results not only generalize the concept of EVB, but also demonstrate an extra highly controllable degree of freedom for electron beam manipulation in addition to OAM.
