Stitching-free 3D printing of millimeter-sized highly transparent spherical and aspherical optical components

Abstract

We demonstrate the fabrication of optical elements on the millimeter scale by stitching-free 3D printing via two-photon polymerization, using a commercial microfabrication system (Nanoscribe GmbH). Previous limitations are overcome by the use of a large writing field objective as well as a novel high transparency resist. The printed optical components are free of stitching defects due to a single step exposure and exhibit an unpreceded glass-like appearance due to the low absorption of the resist material throughout the entire visible wavelength range. We print aspherical focusing lenses, characterize and optimize their shape fidelity, and find their optical performance close to the simulated optimum. For comparison with commercially available glass lenses we also fabricate spherical half-ball lenses of different sizes. The imaging quality of the lenses is very similar, underpinning the powerfulness of our fabrication strategy.

Micro 3D Printing by Two-Photon Polymerization: Configurations and Parameters for the Nanoscribe System

“…The best solution for fabricating macroscale objects therefore depends on the necessary resolution and on how dedicated a user might be to optimizing the printing process. Stitching-free 2PP 3D printing of millimeter-sized optical components was recently demonstrated using a 10×/0.30 microscope objective with a writing field of 1 mm used in DiLL mode, together with the IP-Visio resin [49]. When sub-micrometer resolution is not crucial, but any stitching might interfere with the structure's function, selecting a microscope objective with a low numerical aperture, but a large effective writing field, is highly beneficial.…”

“…3D printing of macroscale structures has potential applications in for example optics, particularly for producing small lenses and other diffractive optical elements [49]. Unlike the other structures shown above, the fabricated Yggdrasil structure (Figure 6) has a size of 560 µ m × 435 µ m, which makes it visible on the substrate with the naked eye.…”

Laser 3D Printing of Inorganic Free-Form Micro-Optics

“…This is a very important issue being recognized in free-form 3D microoptics. Furthermore it allows extinction of any photo-initiator used during the laser photopolymerization, as an organic molecule which is non-preferable due to its absorbance [27] and yellowing effects [28] -both limiting optical performance of microoptics.…”

Multi-Lens Array Full-Field X-ray Microscopy

“…In recent years, additive manufacturing processes that use direct laser exposure have been tested for the production of CRLs [19,20]. This manufacturing process is still slow [21] and, due to the voxel-wise exposure, provides quite rough surfaces compared to lithographic processes.…”