KENBIKYO Vol.50▶No.3 2015
â– Feature Articles: Current Status of the Development of Ultrafast Electron Microscopes in Japan

Ultrafast Electron Diffraction and Deflectometry with Electron Sources Generated and Accelerated by Intense Femtosecond Lasers

Shuji Sakabe, Masaki Hashida, Shigeki Tokita, Shunsuke Inoue, Kensuke Teramoto and Kouta Watanabe

Abstract: A next challenge for advanced electron microscopes is the development of high-speed electron microscope with the high time resolution. As the beginning, ultrafast electron diffraction has been studied. To observe phenomena of irreversible processes, intense short electron pulses must be indispensably developed, but there is an essential problem as the spread of the electron pulse by space charge effect. We are studying the interaction physics of intense femtosecond laser and matters to develop the instruments of ultrafast electron diffraction and deflectometry using laser generated and accelerated electron pulses. In this interaction, electrons (plasma) are instantaneously generated and accelerated in a target by an intense femtosecond laser pulse, and the electron bunch is available as an intense short pulse electron source. The electron pulse source will be intense and short enough for the ultrafast electron diffraction. In this article, the principle of laser acceleration, the compression of laser generated and accelerated electron pulses, the demonstration of imaging a diffraction pattern by a single pulse, and the observation of an laser induced surface wave by femtosecond electron deflectometry are reviewed.

Key words: ultrafast electron diffraction, intense femtosecond lasers, laser electron acceleration, electron deflectometry