A Simple and Rapid Data Extraction Method for the Precision Aspheric Optical Surface Height

Abstract

Nowadays, the application of aspheric optics is becoming more and more popular in the precision optical engineering field. Therefore, it urges the rapid development of the precision machining and measuring technology. Generally, the aspheric optical component is measured by the interferometer. The underlying question is that the figure output by interferometer can’t be always recognized by other analysis software or program though the interferometer has its own unique data processing system. In this paper, a robust, rapid and simple method is presented to interpret the surface height data of the precision machined aspheric optical surface. The optical surface is measured by interferometer. The result figure is split into two parts, one of which is the interferogram picture of the whole aspheric optical surface and the other is the colour reference column indicating the height value. The ratios of the red (R), green (G) and blue (B) are analysed based on the middle of the colour reference column, and the corresponding relationship between the colours and surface height is established and looked as a reference data base. Then the interferogram picture of the whole aspheric optical surface is also analysed and divided according to the red (R), green (G) and blue (B) colours. By comparing the ratios and values of RGB colour, the aspheric optical surface height can be extracted approximately. The feasibility of this method was approved by the extraction processing experiment of a polished aspheric optical surface.