Modeling, fabrication, and metrology of 3D printed Alvarez lenses prototypes.

In this work, we present the fabrication of two 3D printed plano-freeform prototypes, designed in such a way that, when assembled, an Alvarez lens is formed. The freeform surface of each element was mathematically described using Zernike polynomials and verified by implementing an off-axis null-screen test. Additionally, a characterization by refraction of the assembled lens was performed.

Design and fabrication of a lightweight 3D first surface mirror aluminized by DC magnetron sputtering.

Aluminum thin films were deposited on a 3D prototype employing the direct current magnetron sputtering technique to fabricate a lightweight 3D first surface mirror. Before the aluminizing, the surface of the prototypes was evaluated with interferometry and atomic force microscope (AFM). The thin films were characterized using profilometry, UV-Vis spectroscopy, x-ray diffraction, AFM, x-ray photoelectron spectroscopy (XPS), and scanning electron microscopy.

Fabrication of biconvex spherical and aspherical lenses using 3D printing.

In this work, we present the methods of fabrication and characterization of biconvex spherical and aspherical lenses with 25 and 50 mm diameters that have been created via additive technology using a Formlabs Form 3 stereolithography 3D printer. After the prototypes are postprocessed, fabrication errors ≤2.47 for the radius of curvature, the optical power, and the focal length are obtained.

Null-screen design for highly freeform surface testing.

A new alternative to calculate the null-screen for highly freeform or complex surfaces for any desired pattern to be observed on the detector is presented. To validate the proposed method, we used the Zernike polynomials to design complex surfaces with sagittas greater or equal to 40 mm, and peak to valley greater or equal to 30 mm, between the used surface and the best fit sphere. The freeform surfaces were fabricated using a 3D printer and a five-axis CNC machine.

General equations for the null-screen test for aspherical surfaces with deformation coefficients.

A modified approach to calculate the null screen for testing fast convex/concave aspherical surfaces with deformation coefficients is presented. Introducing the aberration polynomial into the equation of the sagitta, the null screens can be generated in a simple way, in contrast to the conventional design method. This approach is easy to implement for the calculation of the null screen since the equations presented here are easy to program computationally.