Oc-3 Zone Plates
Published: Wednesday 15 March 2006 - Updated: Monday 28 March 2011
To demonstrate interference using half period zone plates.
- Microwave apparatus
- Zone plates
- Retort stands
- Tape measure
Click on pictures to enlarge.
The transmitter and receiver are positioned 2 metres either side of the zone plates. It is important to ensure that they are both aligned along the axis. The Zone plate has a focal point of 1 metre. The final position for the receiver is best found in the following manner; position the transmitter 2 metres from the zone plate, remove the two central zones and search with the receiver at the 2 metre mark for a minimum. When this has been found replace the outer zone and a distinct maximum should be observed if alignment has been satisfactory. The contribution of each zone on the wave field at the focus may now be demonstrated.