Design of reflective quarter-wave plates in extreme ultraviolet

Using an optimization method of layer thicknesses based on a genetic algorithm, aperiodic multilayer structures are designed, which display excellent quarter-wave plate (QWP) characteristics for extreme ultraviolet (EUV) radiation in reflection. In addition, a broadband QWP with 3 eV bandwidth in the EUV region, was also designed with the same optimization algorithm and an adapted merit function. The structural and reflective characteristics of single photon energy and broadband reflective QWPs have been explored numerically. Fabricating such optical components could allow polarization control of EUV radiations and ultrafast EUV pulses.