Laser Confocal Interference Multi-Parameter Measurement Method for Spherical Lens

This letter proposes a new, comprehensive laser confocal interference multi-parameter measurement method (CIMPM) to improve the measurement accuracy and efficiency for the multiple parameters of a spherical lens. By integrating laser confocal and sphere interference measurement techniques, the proposed CIMPM uses the laser confocal focusing technique to measure the radius, thickness, and refractivity of a spherical lens, and uses laser interference measurement technique to measure the surface figure. So, this technique achieves high accuracy comprehensive multi-parameter measurements of a spherical lens on a single instrument. Experiments indicate that the proposed CIMPM can achieve a measurement accuracy of 9 ppm for the radius, 3.2.×10^-4 for the thickness, 1.6.×10^-4 for the refractivity, and a peak to valley of λ/20 for the surface figure.