title: High efficiency structured EUV multilayer mirror for spectral filtering of long wavelengths.
abstract: High spectral purity at longer wavelength side is demanded in many extreme ultraviolet (EUV) and soft X-ray (together also referred to as XUV) optical systems. It is usually obtained at the expense of a high loss of XUV efficiency. We proposed and developed a new method based on a periodic, tapered structure integrated with an EUV multilayer. The longer wavelength radiation is scattered/diffracted away by the tapered multilayer structure while the EUV light is reflected. The first proof-of-principle showed a broadband suppression from λ = 100-400 nm with an average factor of 14. Moreover, a high EUV reflectance of 64.7% was achieved, which corresponds to 94% of the efficiency of a regular EUV multilayer mirror.
authors.forename: Qiushi
authors.initials: Q
authors.lastname: Huang
authors.forename: Meint
authors.initials: M
authors.lastname: de Boer
authors.forename: Jonathan
authors.initials: J
authors.lastname: Barreaux
authors.forename: Robert
authors.initials: R
authors.lastname: van der Meer
authors.forename: Eric
authors.initials: E
authors.lastname: Louis
authors.forename: Fred
authors.initials: F
authors.lastname: Bijkerk