Summary
Tangential slope error: less than 0.5 μrad RMS, measured by a 3D profilometer with a sampling pitch of 1 mm after applying a Gaussian low-pass filter with λ = 1 mm. Sagittal slope error: less than 3 μrad RMS, evaluated under the same 3D profilometer conditions. Residual height error: less than 3 nm RMS, measured by a 3D profilometer. Evaluation note: these form errors are evaluated after subtraction of the best-fit Wolter. Surface roughness: less than 1 nm RMS, measured by WLI with a field of view of 1 × 1 mm².
Surface roughness: less than 0.3 nm RMS, measured by WLI with a field of view of 0.1 × 0.1 mm². Substrate material: Si(100). Coating: Au, 50 ± 10 nm. Binder: Cr, 5-10 nm. S/D: 20 μm / 500 μm (No Haze). Chamfer: C0.5 on all edges. Squareness and parallelism: 0.5′.