The Key Technology Of Laser Differential Confocal Interference Measurement For Element Parameters

As the developing of the frontier research fields such as laser fusion system and the ultraviolet light engraving machine, the requirements for the spherical component parameter measurement accuracy is increasingly higher, of which the curvature radius and spherical surface shape parameters of spherical element play a vital role in many high precision scientific research project. In addition, the high accuracy measurement of the spherical element is very crucial for the optical manufacture, as the precision of the optical manufacture depends largely on measurement precision. Therefore, the high precision measurement technology and its equipment research for the spherical element parameters are of great significance.To solve this problem, in this paper, we establish the differential confocal laser interference element parameters measurement system. We make the organic integration of theory of differential confocal laser with phase shifting interference theory and then design and build the laser differential confocal parameters comprehensive measuring light path, the system utilize the laser differential confocal principle to precisely identify the cat’s eye and focus position of spherical elements so as to achieve the high precision measurement of spherical element radius of curvature. At the same time, the system uses the five-step phase-shifting interferometry techniques to achieve high precision inspection for the spherical surface shape. In this paper, the main research work includes: 1) Based on the analysis of the organic integration of differential confocal laser radius of curvature measurement principle and the phase shifting interference surface shape measurement principle, we established the differential confocal laser interference element parameters measuring light path. 2)The design of the laser differential confocal interference light path: with the simulation software Zemax, the system optical simulation model is established to do the simulation design of the collimating lens according to the system requirements and analyze influence of the two sections on each other. 3) The mechanical structural design of the system: the mechanical structure is designed with the Solidworks software and the construction of the system is completed. 4) Experimental verification and error analysis: experiments are do to prove the validity and feasibility of the principle and analyze the interference between the two measurement sections.