FEL2011 - List of Authors (Wijnen, F.J.P.)

Paper	Title	Page
TUPA16	A Simple Spectral Calibration Technique for Terahertz Free Electron Laser Radiation	227
	G. Berden FOM Rijnhuizen, Nieuwegein, The Netherlands R.T. Jongma, F.J.P. Wijnen, H.J.F.M. van der Pluijm Radboud University, Nijmegen, The Netherlands
	Upconversion of terahertz FEL radiation to the optical spectral region allows the use of highly efficient optical detection techniques (such as photo-diodes, spectrometers, array detectors) for sensitive characterization of the THz radiation. For online monitoring of the FEL radiation, a small fraction of the radiation is upconverted to the near-infrared region using a ZnTe crystal and a narrow bandwidth continuous wave (cw) laser operating at 780 nm. The ZnTe crystal does not need any angle tuning, and allows the efficient conversion of all wavelengths longer than 100 μm. Because the upconversion laser is cw, the FEL radiation is automatically temporally synchronized. Furthermore, its narrow bandwidth ensures that the spectral properties of the upconverted light can be directly related to the FEL radiation. In this contribution we demonstrate the upconversion technique for the spectral characterization of THz pulses of FELIX. In the near future, the upconversion spectrometer will be used as online wavelength spectrometer for FLARE, the THz FEL under construction at the Radboud University in Nijmegen which will operate in the 100-1500 μm spectral range.

Paper

Title

Page

A Simple Spectral Calibration Technique for Terahertz Free Electron Laser Radiation

227

G. Berden
FOM Rijnhuizen, Nieuwegein, The Netherlands
R.T. Jongma, F.J.P. Wijnen, H.J.F.M. van der Pluijm
Radboud University, Nijmegen, The Netherlands

Upconversion of terahertz FEL radiation to the optical spectral region allows the use of highly efficient optical detection techniques (such as photo-diodes, spectrometers, array detectors) for sensitive characterization of the THz radiation. For online monitoring of the FEL radiation, a small fraction of the radiation is upconverted to the near-infrared region using a ZnTe crystal and a narrow bandwidth continuous wave (cw) laser operating at 780 nm. The ZnTe crystal does not need any angle tuning, and allows the efficient conversion of all wavelengths longer than 100 μm. Because the upconversion laser is cw, the FEL radiation is automatically temporally synchronized. Furthermore, its narrow bandwidth ensures that the spectral properties of the upconverted light can be directly related to the FEL radiation. In this contribution we demonstrate the upconversion technique for the spectral characterization of THz pulses of FELIX. In the near future, the upconversion spectrometer will be used as online wavelength spectrometer for FLARE, the THz FEL under construction at the Radboud University in Nijmegen which will operate in the 100-1500 μm spectral range.