title: Laser differential confocal lens refractive index measurement.
abstract: A new laser differential confocal lens refractive index measurement is proposed, which uses the absolute zero of the differential confocal axial intensity curve to precisely identify the positions of the objective when the measurement pencil is focused on the vertex of the test lens and the reflector with or without the test lens in the measurement light-path, and then uses aberration compensation and ray tracing facet iterative calculation to obtain the refractive index of the test lens, thereby achieving the high-precision noncontact measurement of lens refractive index. The theoretical analyses and preliminary experiments indicate that the accuracy of the approach can reach about 2.5×10(-4).
authors.affiliation: Key Laboratory of Photoelectronic Imaging Technology and System (Ministry of Education of China), Opto-Electronic College, Beijing Institute of Technology, Beijing 100081, China. zwq669@126.com
authors.forename: Weiqian
authors.initials: W
authors.lastname: Zhao
authors.forename: Yun
authors.initials: Y
authors.lastname: Wang
authors.forename: Lirong
authors.initials: L
authors.lastname: Qiu
authors.forename: Haorong
authors.initials: H
authors.lastname: Guo