Fig.1. Real & imaginary parts of the refractive indices for MgF2 taken from different sources. |
Fig.2. Interpolated real & imaginary parts of the refractive indices for MgF2 taken from Palik’s Handbook. |
Fig.3. Absolute TM efficiency of 316 gr/mm Al echelle in -9 (thick) & -8 (thin) orders at wavelengths of 632.8 nm vs. angle of incidence for different values of RI used in calculations. |
Fig.4. AFM profilometry on G185M grating performed by SPN Digital Nanoscope IIIA before (upper) and after (lower) Cr/Al/MgF2 coating. Vertical scale is the same in both figures. |
Fig.5. Measured (points) and calculated (curves) of –1 order efficiency of G185M grating for NP polarization, plotted vs. wavelength. Efficiency models calculated for the nonconformal MgF2 layer and refractive indices of MgF2 taken from different sources. |
Fig.6. Portion of a trace of grating 1528 taken with the microinterferometer. Both the depth and the profile shape are severely distorted. Compare with the profiles in Figs. 7 and 9. |
Fig.7. Portion of a stylus profilometer trace for the grating shown in Figs. 6 and 9. The stylus radius is 0.1 micron in the axis scanned. Solid: Raw data; dashed: Averaged per method described in the text. |
Fig. 8. Portion of a stylus profilometer trace for a deep echelle grating for IR spectroscopy. This grating, including deep (~57º) sloped facets, a flat top, and sharp bottom, is well resolved due to its extremely long period of ~140 microns. Height is in microns. |
Fig.9. An example of an AFM image of a portion of two adjacent grooves of a ruled grating. The sample serial number is 1528-1-2-3. X is the axis perpendicular to the groove, Y is parallel to the grooves, and Z is the groove height. This is a planar red blazed reflection grating with a groove density of 67.556/mm. The facet shape and roughness are evident. |
Fig.10. Contour plot of AFM data on a 3600/mm ruled grating for EUV normal incidence spectroscopy. Units are microns for the lateral scale and nm in the vertical scale bar. Rough groove edges are apparent. |