3D-printed microscope with illumination for undergraduate wave optics laboratory

TL;DR

The paper addresses high costs and limited access to advanced microscopes in undergraduate optics labs by presenting a complete, low-cost, open-hardware microscope built from 3D-printed parts and off-the-shelf components. It combines an infinity-corrected objective with a compact LED illumination system, allowing quantitative studies of refraction, Newton's rings, and both Fresnel and Fraunhofer diffraction. The authors provide assembly guidance, calibration methods, and a suite of exercises, with an approximate total cost near $500, making wave-optics demonstrations feasible in resource-constrained settings. The work offers a flexible, extensible platform suitable for education and student projects, and it points toward further integrations with spectroscopy, polarization, interferometry, and machine-vision applications.

Abstract

We present an educational tool, a microscope with a video camera, that can be fabricated either from a standard microscope or assembled from inexpensive, commercially available components (objectives, beam splitters, LEDs, linear stages) and 3D-printed elements. Usage of interference filters in combination with white light-emitting diode (LED) illumination enables the quantitative study of optical phenomena such as refraction, interference (e.g., Newton's rings), Fresnel and Fraunhofer diffraction. Thus, we propose an instrument that can be used to illustrate the theoretical foundations of an undergraduate optics course and beyond.

Figures (8)

• Figure 1: Left: components of 3D-printed microscope. Right: microscope.
• Figure 2: A schematic representation of the microscope toolkit. Changeable elements are shown by dashed frames.
• Figure 3: (a) Schematics of the top-illumination scheme. Photo(b) and 3D model(c) of top illumination. (d) Schematics of the collimated light source for nearly parallel light illumination. The positions of Lenses 1 and 2 are determined using the thin lens equation. 3D views of parallel bottom illumination a shown in panels (e) and (f)
• Figure 4: Schematics of the experiment on refraction coefficient determination
• Figure 5: Schematics of the top (a) and bottom (b) geometry for the observation of Newton rings. Newton’s rings pattern under white-light illumination for both geometries shown on panels (c) and (d). Panels (e) and (f) show ring pattern for filtered white LED light ($\lambda\approx532\,$nm) for lenses of different curvatures (dashed circles are shown as a guide to the eye). Panel (f) shows RGB-averaged and normalized intensity instead of direct camera image. Panel (g) show radial dependence of intensity along A-B line on panel (f) (shown in yellow) and the inset show the squared maxima radii as function of the maxima number for two wavelengths $\lambda_1\approx 650\,$nm (higher slope), $\lambda_2\approx 532\,$nm (lower slope) and lens with $R\approx 1\,$cm.