Wavelength switching in an optical klystron

Conference · Sun Dec 31 04:00:00 EST 1995

OSTI ID:238696

Berryman, K W; Smith, T I ^[1]

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1. Stanford Univ., CA (United States)

A symmetric optical klystron consists of two identical undulator sections separated a dispersive section. For a device of a given length, an optical klystron is capable of producing much more bunching, and therefore more gain, than a traditional undulator. Another consequence of introducing dispersion between two undulator sections is that the overall spontaneous radiation pattern results from the interference between the two undulator sections, and as such resembles a standard undulator radiation pattern modulated by a sinusoidal interference term. The presence of several wavelength peaks in the spontaneous lineshape implies an equal number of peaks in the gain spectrum. If the strength of the dispersion section is adjusted to provide nearly equal gain on the two largest of these peaks, then they will compete, and the FEL may switch wavelengths based on noise, cavity length, or other perturbations. We provide the first observations of this behavior, using the FIREFLY system at the Stanford Picosecond FEL Center. In FIREFLY, relative wavelength switching by more than 3%--more than twice the laser linewidth-has been observed by varying dispersion section strength, while at intermediate points stable switching has also been observed as a function of cavity length.

• Research Organization: Brookhaven National Lab., Upton, NY (United States)
• OSTI ID: 238696
• Report Number(s): BNL--61982-Absts.; CONF-9508156--Absts.; ON: DE96002729; CNN: Grant N00014-94-1-1024
• Country of Publication: United States
• Language: English

Related Subjects

43 PARTICLE ACCELERATORS
BEAM BUNCHING
FREE ELECTRON LASERS
KLYSTRONS
WAVELENGTHS
WIGGLER MAGNETS