Evolution of a finite pulse of radiation in a high-power free-electron laser

Journal Article · Sun Dec 01 04:00:00 EST 1991 · IEEE Journal of Quantum Electronics (Institute of Electrical and Electronics Engineers); (United States)

DOI:https://doi.org/10.1109/3.104129· OSTI ID:5615610

Ting, A; Hafizi, B; Sprangle, P; Tang, C M ^[1]

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1. Naval Research Lab., Washington, DC (United States). Plasma Physics Div.

The development of an optical pulse of finite axial extent is studied by means of an axisymmetric time-dependent particle simulation code for different rates of tapering of the wiggler field. The results provided in this paper illustrate a number of the physical phenomena underlying the free-electron laser mechanism. These include: suppression of the sideband instability; the role of gain focusing versus that of refractive guiding; efficiency enhancement; and pulse slippage. It is found that a significant reduction in the sideband modulation of the optical field can be achieved with a faster tapering of the wiggler parameters. Increasing the tapering rate also reduces refractive guiding, causing the optical wavefronts to become more convex, thus spreading the optical field into a larger cross section. The corresponding enhancement of the peak output power is associated with an increased lateral extent of the optical field rather than an increase in the field amplitude.

• OSTI ID: 5615610
• Journal Information: IEEE Journal of Quantum Electronics (Institute of Electrical and Electronics Engineers); (United States), Journal Name: IEEE Journal of Quantum Electronics (Institute of Electrical and Electronics Engineers); (United States) Vol. 27:12; ISSN 0018-9197; ISSN IEJQA
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
426002* -- Engineering-- Lasers & Masers-- (1990-)
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47 OTHER INSTRUMENTATION
AMPLIFICATION
BEAM FOCUSING MAGNETS
ELECTRICAL EQUIPMENT
ELECTROMAGNETS
ELECTRONIC EQUIPMENT
EQUIPMENT
FREE ELECTRON LASERS
FREQUENCY MODULATION
FUNCTION GENERATORS
GAIN
LASERS
MAGNETIC FIELDS
MAGNETS
MODULATION
OPTICAL SYSTEMS
PEAK LOAD
PULSE GENERATORS
TIME DEPENDENCE
WIGGLER MAGNETS