Glass plates with 12 different single and double diffraction apertures for quantitative diffraction experiments.

Diameter of support: 40 mm
Aperture irregularities: <1 µm

Single apertures:
Diameters: 20, 30, 50, 100, 200 and 500 µm

Double apertures:
Separations: 100, 200 and 400 µm
Diameter: 50 µm

Rectangular apertures:
Dimensions: 70 x 70 µm², 200 x 200 µm² and 70 x 200 µm²