The Free-Electron Laser as a Laboratory Instrument

Abstract

A free-electron laser (FEL) with a component cost, including the accelerator, of approximately $300k, has lased at a wavelength of 85 μm with ≈12 ps micropulse duration, achieving a power growth four orders of magnitude greater than the coherent spontaneous emission, and with a small-signal, single-pass gain of 21%. The price is about an order of magnitude less than other FELs for the far infrared, and transforms the device from the role of a national facility to that of a laboratory instrument. Cost reduction was achieved by employing several novel features: a microwave cavity gun for the accelerator, a staggered-array wiggler, and an on-axis hole in the upstream cavity mirror for electron ingress and radiation egress. Copyright 1995 IEEE