Near-normal-incidence extreme-ultraviolet efficiency of a flat crystalline anisotropically etched blazed grating.
We have measured the extreme-ultraviolet (EUV) efficiency at an angle of incidence of 10 degrees of a flat crystalline anisotropically etched blazed grating. The measured efficiencies are high for uncoated gratings and agree well with a calculated model derived from a reasonable estimate of the groove profile. The highest groove efficiencies derived from the measurements are 48.8% at 19.07 nm and 64.1% at 16.53 nm for the -2 and -3 orders, respectively, which are comparable to the best values obtained yet from a holographic ion-etched blazed grating. This presents opportunities to instrument designs for high-resolution EUV spectroscopy in astrophysics where high efficiency in high orders is desirable.
U.S. Naval Research Laboratory, Code 7655.3, 4555 Overlook Avenue, SW, Washington, D.C. 20375, USA. michael.kowalski@nrl.navy.mil
Michael P
MP
Kowalski
Ralf K
RK
Heilmann
Mark L
ML
Schattenburg
Chih-Hao
CH
Chang
Frederick B
FB
Berendse
William R
WR
Hunter