Mathematical model of interferometric optical probe

The advantages of the freeform surface is obviously in optical system application: higher image quality, larger view field, simplified system and more design degrees of freedom. But, the large application of the freeform surface is limited by the difficulty of its manufacture. Measurement is the base of optical fabrication. In order to achieve the high precision freeform surface, the surface should be measured accurately. High precision freeform surface measurement technology is one of the most important problem in the field of optical fabrication. A new measurement method has been proposed which is different from the existing free-form surface measurement instruments, and it is proved in theory that can achieve high precision measurement for free-form surfaces. In this paper, a complete mathematical model is established for the probe part through ray tracing, so as to obtain the object-image relationship data of light passing through each optical element. Using the point set, the wave image of each surface is obtained, the optical path difference of the light is calculated, and the corresponding interference diagram is drawn. This process is principle verification. Contrary to the simulation process, in the process of measuring, the interferogram is obtained first, and then the deviation value is calculated.