Observation of Power Instability and Multimode Behavior in a Far-Infrared Free-Electron Laser.

摘要

Measurements of the time dependence and the frequency spectrum of the output power in the far-infrared free-electron laser are reported. In typical light pulses of 20-50 microsec we have observed unexpected oscillations of the laser output with a characteristic period of 5 microsec. At the same time, the laser frequency swept over a discreet set of frequency modes, separated by 1.3 GHz. We also present measurements of the gain and loss of the optical mode and discuss the problem of the accelerator terminal voltage drop in a single electron beam pulse with relation to the light spectrum. Reprints. (jhd)