In strong-field laser physics, ponderomotive energy is the cycle-averaged quiver energy of a free electron in an electromagnetic field.[1]


The ponderomotive energy is given by


where is the electron charge, is the linearly polarised electric field amplitude, is the laser carrier frequency and is the electron mass.

In terms of the laser intensity , using , it reads less simply:


where is the vacuum permittivity.

Atomic units

In atomic units, , , where . If one uses the atomic unit of electric field,[2] then the ponderomotive energy is just


The formula for the ponderomotive energy can be easily derived. A free particle of charge interacts with an electric field . The force on the charged particle is


The acceleration of the particle is


Because the electron executes harmonic motion, the particle's position is


For a particle experiencing harmonic motion, the time-averaged energy is


In laser physics, this is called the ponderomotive energy .

See also

References and notes

  1. ^ Highly Excited Atoms. By J. P. Connerade. p. 339
  2. ^ CODATA Value: atomic unit of electric field