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Development of non destructive high precision test methods for aspheric components and tools in optics

Objective


The project has resulted in the assessment of various conventional testing techniques, and the development of several innovative testing techniques, and tools.
One of these innovative test techniques showed very promising results: a major part of the relevant aspheric surfaces could be measured with this technique.
An industrial version of this testing technique is currently under development and it is expected that this will enable the manufacture of aspheric components for various lens systems with the ever increasing accuracy required.
ASPHERIC OPTICAL COMPONENTS PLAY A MAJOR ROLE IN HIGH VOLUME ARTICLES LIKE CD-PLAYERS. THIS ROLE IS ALSO INCREASING IN TV-SYSTEMS AND CAMERAS. THE AVAILABILITY OF METHODS TO ASSESS THE QUALITY OF ASPHERIC COMPONENTS AND OF THE MOULDS TO MAKE THOSE COMPONENTS IS ESSENTIAL FOR MAINTAINING A LEADING POSITION IN THE FIELD OF ASPHERIC OPTICS.

NO RELIABLE METHOD YET EXISTS TO ASSESS THE QUALITY OF ASPHERIC SURFACE WITH A PRECISION AS NEEDED IN OPTIC. THE MOST SENSITIVE PROBLEMS OCCUR FOR THE LARGE NUMERICAL APERTURE, ESPECIALLY IN MEASURING AND CHECKING THE QUALITY OF MOULDS.
THE OBJECTIVE OF THE RESEARCH PROGRAMME IS TO PROVIDE TECHNIQUES FOR BOTH THE ABSOLUTE MEASUREMENT OF ASPHERIC SURFACES AND COMPARISON OF SURFACES.
AS NO TECHNIQUE WILL COVER THE FULL RANGE, DIFFERENT TECHNIQUES WILL BE INVESTIGATED. THESE TECHNIQUES WILL BE:

A) THE SHEAR INTERFEROMETER
B) THE SCHLIEREN OPTICS
C) THE TWO-LAMBDA INTERFEROMETER
D) THE RONCHI TEST
E) THE INTERFEROMETRY WITH COMPUTER GENERATED HOLOGRAMS.

Funding Scheme

CSC - Cost-sharing contracts

Coordinator

Philips Gloeilampen Fabrieken NV
Address

5600 JM Eindhoven
Netherlands

Participants (2)

Cerco
France
Address
Zone Industrielle De Courtaboeuf
91940 Les Ulis
UNIVERSITAET STUTTGART
Germany
Address
Keplerstrasse 7
70174 Stuttgart