ABSTRACT
Many of the most promising uses of the FEL can be envisaged in those wave-length regions where efficient tunable high-power lasers do not operate. Figure 4.1 suggests that there would be particular interest in FELs operating in the infrared or farinfrared region where they are expected to furnish a considerable amount of power compared to conventional laser sources. This region is of primary interest for solid-state physics, and at shorter wavelengths FELs may be an interesting source for chemical and molecular-spectroscopy studies.
