Large-scale optical diffraction tomography for inspection of optical plastic lenses

TL;DR

This paper introduces a high-resolution optical diffraction tomography method for detailed 3-D refractive index mapping of plastic lenses, enabling precise inspection and quality control in optical manufacturing.

Contribution

The study presents a novel large-scale ODT technique with unprecedented RI sensitivity and resolution for inspecting optical plastic lenses.

Findings

Achieved RI sensitivity of dn = 4.21 x 10^-5

Reconstructed 3-D RI maps of plastic lenses and spheres

Demonstrated potential for optical lens quality inspection

Abstract

Herein is presented an optical diffraction tomography (ODT) technique for measuring 3-D refractive index (RI) maps of optical plastic lenses. A Mach-Zehnder interferometer was used to measure multiple complex optical fields of a plastic lens immersed in RI matching oil, at various rotational orientations. From this, ODT was used to reconstruct a 3-D RI distribution of the plastic lens with unprecedented RI sensitivity (dn = 4.21 x 10^-5) and high resolution (12.8 um). As a demonstration, 3-D RI distributions of a 2-mm-diameter borosilicate sphere and a 5-mm-diameter plastic lens