激光差动共焦非球面顶点曲率半径测量方法

Aiming at the high-precision and universal measurement of the apex radius of curvature of rotationally symmetrical aspheric optical elements with different quadric constants, a laser differential confocal-based aspheric apex radius of curvature measurement method is proposed. This method uses circular pupil technology to make the measured confocal point of the aspheric element close to the center of the apex spherical sphere. Using the differential confocal technology, the cat's eye point and the confocal point of the measured aspherical component are precisely aimed and positioned respectively, and the actual vertex radius of curvature is measured. Through theoretical simulation analysis, the relationship between the size of the circular aperture and the theoretical deviation of the vertex radius of curvature is obtained, and the actual measured value is compensated. Furthermore, high-precision and universal measurement of the apex radius of curvature of rotationally symmetrical aspheric elements with different quadric constants are realized. Theoretical analysis and experimental results show that the relative accuracy of this method for measuring the apex radius of curvature of rotationally symmetrical aspherical elements is less than 0.01%. It provides a brand-new technical means for the high-precision and universal measurement of the apex radius of curvature of aspheric optical elements.