Measuring chromatic aberrations in imaging systems using plasmonic nano-particles

TL;DR

This paper introduces a simple, cost-effective method to measure chromatic aberration in optical systems by analyzing the extinction spectra of metallic nanoparticles within the focal plane, applicable to high NA microscopes.

Contribution

It presents a novel technique to assess chromatic aberration using nanoparticle spectra, offering rapid and accurate measurements for complex microscopy systems.

Findings

Method accurately retrieves chromatic focal shift in high NA objectives.

Applicable to complete microscopy systems for quick aberration assessment.

Enables straightforward implementation without complex interferometry.

Abstract

Chromatic aberration in optical systems arises from the wavelength dependence of a glass's refractive index. Polychromatic rays incident upon an optical surface are refracted at slightly different angles and in traversing an optical system follow distinct paths creating images displaced according to color. Although arising from dispersion, it manifests as a spatial distortion correctable only with compound lenses with multiple glasses and accumulates in complicated imaging systems. While chromatic aberration is measured with interferometry, simple methods are attractive for their ease of use and low cost. In this letter we retrieve the longitudinal chromatic focal shift of high numerical aperture (NA) microscope objectives from the extinction spectra of metallic nanoparticles within the focal plane. The method is accurate for high NA objectives with apochromatic correction, and enables rapid assessment of the chromatic aberration of any complete microscopy systems, since it is straightforward to implement