A zone plate is illuminated with parallel laser light. The focal points of several orders of the zone plate are projected on a ground glass screen.
- find out that optical lenses can be completely different from what you are used to
- interference is used to produce effects commonly achieved with diffraction
- the use of a laser lightsource provides clear results
- The laser beam must be widened so that the zone plate is well illuminated. It must be assured that the laser lightbeam runs parallel over several meters.
- The focal points of several orders of the zone plate are projected on a ground glass screen. The focal lengths to be determined are plotted against the reciprocal value of their order.
- The radii of the zone plate are calculated.
What you can learn about
- Huygens Fresnel principle
- Fresnel and Fraunhofer diffraction
- Fresnel's zone construction
- Zone plates