Abstract

High power free electron lasers (PEL) can produce significant amounts of harmonic radiation. These harmonic components represent a substantial damage threat to the optical elements comprising the laser resonator. In this paper we discuss the merits of using blind gratings in both the paraboloid and grazing incidence hyperboloid mirrors of a 1.06-micron FEL under construction by the Boeing Aerospace Company. Grating designs developed for use at grazing incidence are not very efficient for dispersing the harmonics. However, blind gratings positioned in the paraboloid exhibit better filtering capability.

© 1988 Optical Society of America