The effective density matrix of the radiation field in the free-electron laser is computed under realistic initial conditions for the electrons and photons. The field is predicted to be a superposition of a coherent state and a chaotic state. The width of the distribution in the coherent-state expansion is given by the sum of classical and quantum-mechanical initial fluctuations of the electron beam.
All Science Journal Classification (ASJC) codes
- Atomic and Molecular Physics, and Optics