Gallery
Optical characterisation of a Multi-Zone-Hologram
Fig. 10.1. Sketch of the MZ-CGH verification setup
Fig. 10.1. Sketch of the MZ-CGH verification setup
For various measurement and adjustment tasks, computer-generated holograms (CGHs) with several zones (MZ-CGHs) are used. These are diffractive optical elements with the ability to form almost arbitrarily shaped wave fronts. The figure shows a setup for a measurement systems analysis of the applied CGHs. For example, the straightness of the axis, defined by the series of spots, is verified with an accuracy in the sub-micron region, which is essential for the lens adjustment.
Fig. 10.2 The figure shows schematically the zones of a CGH which is used in the project.
Fig. 10.2 The figure shows schematically the zones of a CGH which is used in the project.
Fig. 10.3 Left: Breadboarding of a MZ-CGH in front of an interferometer with a reference sphere installed on a high-precision air-bearing Linear Stage. Right: A MZ-CGH, illuminated with white light, acts as a diffraction grating and decomposes the light into its constituent colours.
Fig. 10.3 Left: Breadboarding of a MZ-CGH in front of an interferometer with a reference sphere installed on a high-precision air-bearing Linear Stage. Right: A MZ-CGH, illuminated with white light, acts as a diffraction grating and decomposes the light into its constituent colours.
Fig. 10.4 Spot (point-spread-function) of the zone number 3 (see Fig. 10.2) of the MZ-CGH; logarithmic pseudo-colours. Left: Simulation, right: Measurement (camera image). The complex diffraction pattern arises due the particular shape of the aperture stop.
© MPE
Fig. 10.4 Spot (point-spread-function) of the zone number 3 (see Fig. 10.2) of the MZ-CGH; logarithmic pseudo-colours. Left: Simulation, right: Measurement (camera image). The complex diffraction pattern arises due the particular shape of the aperture stop.
© MPE