Ff. Baryshnikov et al., OPTICAL CAVITIES FOR HIGH-POWER FREE-ELECTRON LASERS, Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment, 405(2-3), 1998, pp. 242-247
A theoretical investigation is made on the electromagnetic field in a
crossed-flute cavity. It is shown that the caustic of the held. which
has a small transverse dimension at the cavity center. expands strongl
y and assumes an annular shape on the mirrors. The cavity is relativel
y short and can have a central hole, so that it can be used in high po
wer free electron lasers.