Papers by Author: Q.D. Zhu

Abstract: Null compensator method is a popular aspheric surface testing method. However null compensator has the characteristics of complex structure, high price and poor universal property. This paper proposed to test aspheric surface by a partial compensation lens (PCL) to overcome the defect. This novel PCL method is designed to partially compensate the wave aberration caused by the aspheric surface, which allow some residual wave aberration exists. Research was conducted on measurement principle, design method of PCL. The experiment results show the feasibility and validity of this method.

Abstract: As aspheric surfaces are more often used in optical systems, suitable error evaluation methods and suitable accuracy calibration methods for related test instruments are urgently required. The two unsolved but important issues are addressed. For evaluation of aspheric surfaces, a scheme is proposed to separate the surface errors into radius error and local error. The effects of the two errors on image quality are discussed. For test instrument calibration, a practical method using a defocused spherical surface is described and verified with an absolute testing instrument based on laser deflectometry, which was developed at Beijing Institute of Technology. The feasibility of the schemes is shown and experimental results are presented.