Tongji Univ, IPOE, Dept Phys, Shanghai 200092, Peoples R China
; Kings Coll London, Dept Phys, London WC2R 2LS, England
; BESSY, D-12489 Berlin, Germany
; Chinese Acad Sci, BSRF, Inst High Energy Phys, Beijing 100039, Peoples R China
; CCLRC, Daresbury Lab, Warrington WA4 4AD, Cheshire, England
The polarization state of the BESSY UE56/1-PGM beamline radiation in the broad wavelength range of 12.7-15.5 nm was measured using a molybdenum/silicon transmission phase retarder and a reflection analyzer with aperiodic multilayer interference structures, which can broaden the spectral response of these optical elements. The characteristics of the circular polarized undulator radiation, as well as the polarization properties of the two polarizing elements, were determined by a complete polarization analysis. Furthermore, the polarization of the radiation as a function of the undulator shift setting was also measured at the wavelength of 13.1 nm by use of the broadband phase retarder-analyzer pair. (c) 2007 American Institute of Physics.