The blank is the thick substrate material upon the surface of which the diffraction grating resides. The standard blank material is annealed Pyrex (T.M. Corning, Inc.) glass. Other materials are available upon request; for example, fused silica, Zerodur alloy, CVD silicon carbide, stainless steel, aluminum, Kanigen copper, and others.
Tolerances on length and width: + or - 0.1 mm; thickness: + or - 0.2 mm; concave radius: + or - 0.2%.
Ruled Area
The ruled area is generally the same as the blank size (called Size in the tables), less a 2 mm border.
Quality Certificate
Each shipment of gratings contains a certificate of conformance assuring quality and traceability.
