A scheme for electron acceleration by two crossing chirped lasers has
been proposed. An important effect of a frequency chirp of the laser is
investigated. Two high intensity chirped lasers, with the same amplitude
and frequency, crossing at an arbitrary angle in a vacuum, interfere,
causing modulation of laser intensity. An electron experiences a
ponderomotive force due to the resultant field of lasers and gains
considerable energy. For a certain crossing angle, the electron gains
maximum energy due to the constructive interference. A frequency chirp of
the laser plays an important role during the electron acceleration in a
vacuum. The electron momentum increases due to the frequency chirp. Hence,
the electron energy is enhanced during acceleration.