Research on micro/nanometre measuring technique of optical aspheric surface

The machining accuracy of optical aspheric surface can reach nanometre, but micro/nanometre measurement is the bottleneck for us to improve the accuracy. Aiming at various influential factors during the high-precision aspheric surface testing, the building up of three-dimensional nanometre motion platform is the key technology. The movement of high precision linear motor on the motion platform is controlled by computer. Then the motors drive the laser senor to the position (X, Y, Z) on the aspheric surface which is needed to inspect. Then the position is inspecting by the sensor built in the platform. Through data processing and analyzing, the result of analysing and evaluation of the aspheric surface are got. At last, this measurement system can provide data for compensation processing to the numerical machine tools to improve the profile accuracy of the aspheric surface.