W/C, W/Ti, Ni/Ti, and Ni/V multilayers for the soft-x-ray range: experimental investigation with synchrotron radiation

An experimental investigation of W/C, W/Ti, Ni/Ti, and Ni/V multilayers is presented that uses synchrotron radiation in the soft-x-ray energy region between 100 and 1500 eV with special emphasis on the water window. The multilayers were designed as normal incidence reflectors and for polarimetry purposes around the Brewster angle. Both reflection and transmission multilayers were prepared for use as linear polarizers and phase retarders, respectively, to produce or analyze circularly polarized light. Their period was optimized to achieve maximum reflectance at the 1s absorption edge of C (284 eV) and the 2p edges of a (454 eV) and V (512 eV), respectively. At these edges the multilayers show an enhancement of reflectance and energy resolution that is in accordance with theoretical calculations. (C) 1998 Optical Society of America.