Optimization of hybrid polymer materials for 2PP and fabrication of individually designed hybrid microoptical elements thereof

Abstract

In the last decade, two-photon polymerization (2PP) has gained increasing interest for the production of individually shaped 3D structures. For the successful implementation of 2PP within a production chain for the industrial manufacturing of optical microstructures, advanced material properties of the photo polymer are required. The usable laser dynamic range, shape accuracy as well as surface roughness play a crucial role. In this publication, we present the results of an iterative optimization process aiming at a material applicable for 3D structures written by 2PP. The special focus here lies on the influence of the photo initiator and stabilizer on the usable laser dynamic range and shape fidelity. The application of the optimized photo polymer for the production of a complex prism array, which could be used as master mold, is also shown.

Selective Surface Smoothening of Polymer Microlenses by Depth Confined Softening

“…An MLA with a 3 × 3 test array of concave single lenses of 50 × 50 µm 2 width and 50 µm height from the base to tip at the four corners and with a maximal sag depth of 40 µm was chosen. This diffuser array and a microprism array were fabricated with 2PP on a glass substrate ( Figure a,f) followed by transfer into UV PDMS (Figure b,g) and then thermal NIL into PMMA (Figure c,h) . When PMMA was exposed with 172 nm VUV (465 mJ cm −2 at 3 mm distance from source) and annealed (similar to the Figure c), the sharp features can be preserved while the roughness created by scanning lithography is cleared (Figure d,i).…”

Optically Clear and Resilient Free-Form <em>&micro;</em>-Optics 3D-Printed via Ultrafast Laser Lithography

“…In 3DLL a well chosen photoinitiator (PI) can improve fabrication throughput and structure qualities for a material used [6,7,[19][20][21]. The set of fabrication parameters needed for structuring material is generally refereed as fabrication window.…”

“…They are choice material for 3D femtosecond laser structuring due to several convenient features. Those include optical transparency in the visible part of the spectrum [4] and use of photoinitiators absorbing the UV radiation [5][6][7]. Later makes them perfectly suitable for multiphoton polymerization [5,8] achieved by ultrafast laser and employed in true free-form structuring by 3D laser lithography (3DLL) [9].…”

Faceted structure: a design for desired illumination and manufacture using 3D printing

“…In computer graphics domain, Weyrich et al create the idea of "microfacet height field" by series of algorithms to obtain a custom reflectance [19]. Independently, we see some faceted structures in micro dimensions called mirror cells arrays fabricated by two photon polymerizations in the recent literature [20,21].…”