Abstract

The development of ultrashort laser pulses has resulted in photoelectron pulses in the hundred-femtosecond regime for use in time-resolved structural studies in a variety of chemical processes.¹ More recently, rf-bunched electrons have been compressed with magnetic fields to produce 50-fs electron pulses² with mega-electron-volt energies. In this work we show how, by using an electron-acceleration process driven by optical rectification in a crystal, one can produce electron pulses with subfemtosecond durations and how these electrons can be used to produce significant amounts of attosecond-duration number-state- squeezed transition radiation from thin metallic targets. The method is straightforward and can be implemented by using currently available laser technology.

© 1995 Optical Society of America