Fresnel zone plate

Function and Applications

To investigate the generation of convergent and divergent light beams with the assistance of Fresnel's zone theory.

Equipment and technical data

• The diaphragm has a system of 40 light and dark rings.
• Limit circles between the rings have a diameter d_n = 1.2 (n)^0.5 mm (n = 1, 2, 3...40).
• Focal distance for He-Ne light: 56.9 cm.
• Dimensions (mm): 50 × 50.