The Design Of Partial Compensator For Convex Aspheric Surface Testing

The application of the aspheric optical components becomes gradually extensive in modern optical products, because aspheric surfaces have the advantages of improving the image quality, expanding the field of view, reducing the number of optical components, reducing the volume and weight of the system. Compared with the spheric surface, aspheric one has more complexity and diversity. Thus, the design and the manufacture of aspheric optical components rely on advanced measurement technology as a precondition. In particular, the measurement of convex aspheric needs a special method that is different from the measurement of spheric or concave surface, because convex surface can diverge rays. In this thesis, the measurement of the surface figure error of convex asphere is based on partial compensating principle and digital moire phase-shifting interferometry. The following four aspects are studied focusing on the design of the partial-compensator which is used to test the convex aspheric surface.Firstly, a single lens is designed as partial-compensator to partially compensate the aberration of the tested convex asphere with small relative aperture. The structure, the design process, the optimization method, and the compensation results of this partial compensation system are given.Secondly, according to the definition and the formula of slope asphericity, the relationship between the slope asphericity and the parameters of asphere is studied. Afterwards, the compensation ability of single lens partial-compensator is evaluated and it is proved that the partial-compensator has a large range of compensation.Thirdly, for the convex aspheric surface with large relative aperture, a compensator of new structure is designed, which is a catadioptric partial-compensator. The structure, the design process, the optimization method, and the compensation results of this partial compensation system are given. In addition, this compensator is proved to have the advantages of simple structure, low requirements on design and fabrication compared with the null compensator.At last, in order to verify the feasibility of the method proposed in this thesis, the measurement of convex aspheric surface is simulated and the surface error is solved with partial compensating principle and digital moire phase-shifting interferometry.The testing of convex aspheric surface is studied and the design of the partial-compensator is the key technologies in this thesis. The partial-compensator designed in this thesis has the advantages of simple structure and large range of compensation, which will reduce the difficulty of design and manufacture and reduce the cost in the application of convex aspheric surface testing.