Sustained saturation in a free-electron laser oscillator at perfect synchronism of an optical cavity.
The first observation of sustained saturation in a free-electron laser (FEL) oscillator at perfect synchronism of an optical cavity is presented. A simultaneous measurement of FEL power and absolute detuning length of the optical cavity ( deltaL) has clearly shown that the FEL efficiency becomes maximum at deltaL = 0.0+/-1 microm, although it has been considered that only a transient state exists at deltaL = 0 due to the well-known laser lethargy effect. The observed efficiency detuning curve is well reproduced by our numerical simulation including a small shot-noise effect.
Nishimori
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Free-Electron Laser Laboratory, Advanced Photon Research Center, Kansai Research Establishment, Japan Atomic Energy Research Institute, 2-4 Shirakata-Shirane, Tokai, Naka, Ibaraki 319-1195, Japan. nisi@milford.tokai.jaeri.go.jp
Hajima
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Nagai
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Minehara
E J
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