Harmonic generation in the free-electron laser offers a possible means to extend the wavelength range of the device towards high frequency. Numerical solutions to the basic equations describing this process are shown for cw operation using a linearly polarized wiggler. Higher harmonic emission becomes enhanced as the magnetic field is increased and as the energy spread in the electron beam is reduced.

• Received 3 August 1981

DOI:https://doi.org/10.1103/PhysRevA.25.426