The demand for disposable optics, especially in biomedical fields involving point of care testing systems has led to navigation for new low-cost and high quality optics fabrication processes. We demonstrate that 3D-printing of optics allows on-demand fabrication of polymer lenses at a low price, when no expensive initial tooling expenses are required. However, achieving high surface quality imaging optics has been challenging primarily when the lens diameter is greater than fivefold of a millimeter. In this work, we demonstrate an imaging quality 3D-printed polymer lens with high surface quality of RMS = 0.92 ± 0.33 nm (δ, N=25) and surface profile deviation of ± 500 nm within 0.5 inch aperture diameter. The 3D-printing method is based on Luxexcel’s Printoptical® Technology, using modified ink-jet printheads, by depositing micro-droplets of Opticlear, which is a UV-curable polymer with an inhomogeneity index of 1.1-1.3×10-5 for 0.5 mm plate. We demonstrate a spatial resolution limit below 5 μm using a USAF1951-1x imaging resolution target for the 3D-printed singlet lens that is comparable to an off-the shelf commercial LA1509 N-BK7 plano-convex lens with the same specification parameters. Another application area of the inch-scale printed lens is in low-cost DSLR cameras. Experimental photos taken with a 3D-printed singlet lens and a commercial glass lens are nearly identical. As a result, manufacturing of 3D-printed singlet lenses with repeatability of ±200 nm for small or medium volume production at once becomes feasible by placing the printheads in parallel. We expect further developments towards achromatic optics by development of new 3D-printable polymers.
A combination of light-emitting diodes (LEDs) with freeform optics has been recently investigated widely for energy efficient illumination due to its high optical performance and compact size. The freeform optics design methods are application specific. The transformation of the light source into the target irradiance distribution using freeform optics usually leads to solving an inverse problem, which can be formulated by using a point light source, geometrical optics, monotonic ray bending and lossless system. Here, a customized algorithm is proposed to design freeform lenses for both LED source based simple uniform rectangular illumination and collimated light source based complex image target irradiance distributions by numerically solving the elliptic Monge-Ampère equation. The optical performance of the lenses is examined theoretically by using commercial ray tracing software.
Additive manufacturing (also called as 3D printing), a layer-by-layer printing of patterned material, is considered as novel option for low-cost and rapid manufacturing of optics. Recently, 3D printed ISO-standard ophthalmic lenses have been produced using Printoptical® technology (US Patent No. 13/924,974): a modified ink-jet printing technology that deposits micro-droplets Opticlear, which is a PMMA-like UV-curable polymer. In our work, the Printoptical® technology is further extended to freeform lenses using Opticlear, which is a PMMA like UV-curable polymer. The metrology of the freeform lenses is studied using white-light interferometry and VR-3000 series 3D surface profile macroscope.