FEL2011 - List of Authors (Mansten, E.)

Paper

Title

Page

Transverse Coherence and Polarization Measurement of Coherent Femtosecond Pulses from a Seeded FEL

458

J. Schwenke, N. Čutić, F. Lindau, S. Werin
MAX-lab, Lund, Sweden
E. Mansten
Lund University, Division of Atomic Physics, Lund, Sweden

We report on measurements of the transverse coherence and polarization of light pulses at 131 nm generated by a seeded free-electron laser. Our setup consists of two undulators. The first undulator is used to energy modulate relativistic electron bunches (375 MeV) with the help of an ultraviolet seed laser pulse at 263 nm. The electron bunches subsequently pass through a dispersive section, where the energy modulation is converted into microbunching, and then enter the radiator undulator. The radiator is an APPLE-II type undulator set to be in resonance for 131 nm radiation. The radiator emits coherent femtosecond pulses up to the 6th harmonic of the seed laser [1]. The state of polarization of the pulses can be tuned from planar to helical polarization by shifting the undulator magnets. The emitted pulses are analyzed with a grating spectrometer. A double slit aperture is positioned in the beam in order to determine the transverse coherence of the light pulses by analyzing the fringe visibility. Furthermore, the generation of circular polarized light is demonstrated. The polarization state of the light pulses is measured with a Rochon prism polarizer.
[1] Cutic et al, Phys. Rev. Spec. Top-AC 14, 030706 (2011)

Slides THOB4 [1.173 MB]

Paper	Title	Page
THOB4	Transverse Coherence and Polarization Measurement of Coherent Femtosecond Pulses from a Seeded FEL	458
	J. Schwenke, N. Čutić, F. Lindau, S. Werin MAX-lab, Lund, Sweden E. Mansten Lund University, Division of Atomic Physics, Lund, Sweden
	We report on measurements of the transverse coherence and polarization of light pulses at 131 nm generated by a seeded free-electron laser. Our setup consists of two undulators. The first undulator is used to energy modulate relativistic electron bunches (375 MeV) with the help of an ultraviolet seed laser pulse at 263 nm. The electron bunches subsequently pass through a dispersive section, where the energy modulation is converted into microbunching, and then enter the radiator undulator. The radiator is an APPLE-II type undulator set to be in resonance for 131 nm radiation. The radiator emits coherent femtosecond pulses up to the 6th harmonic of the seed laser [1]. The state of polarization of the pulses can be tuned from planar to helical polarization by shifting the undulator magnets. The emitted pulses are analyzed with a grating spectrometer. A double slit aperture is positioned in the beam in order to determine the transverse coherence of the light pulses by analyzing the fringe visibility. Furthermore, the generation of circular polarized light is demonstrated. The polarization state of the light pulses is measured with a Rochon prism polarizer. [1] Cutic et al, Phys. Rev. Spec. Top-AC 14, 030706 (2011)
	Slides THOB4 [1.173 MB]