Structure:

- glass wafer
- the grating is formed on the layer of chalcagenid glass
- the grating top surface is aluminium

Pattern types:

1- Dimensional (in the X or Y direction)

Pattern height:

> 55 nm provides good image contrast

Geometry:

parallel ridges

Period:

278 nm (3600 periods/mm)

Accuracy:

±1nm

Size:

diameter 12,5 mm, thickness - 2,5 mm

Effective area:

central diameter 9 mm.