DESIGN OF A SHORT-PULSE, FAR-INFRARED FREE-ELECTRON LASER WITH A HIGHLY OVERMODED WAVE-GUIDE

We report the design of a long wavelength extension to the free electr on laser for infrared experiments. A parallel plate is inserted in the resonator to reduce diffraction losses. It will be shown that with a 10 mm gap waveguide, single transverse mode operation can be expected over a wavelength range from 300 down to 40 mu m, allowing pulses as s hort as a few optical cycles to be produced. (C) 1997 American Institu te of Physics.