Additive manufacturing of double-sided centimeter-scale optics.

In this article we demonstrate rapid manufacturing of an illumination quality double-sided centimeter-scale optics without any post-processing. Two methods are presented: additive manufacturing (AM) using an optically transparent material with a water-soluble support material (support method), and alternatively, using only the optically transparent material but flipping the optics mid-process (flipping method). The main advantage of the flipping method is that only one material is needed. However, the use of support material is more straightforward, allows better alignment between the two sides of the lens and enables more complex lenses manufactured in the future. Both methods result in sufficient surface quality, i.e. surface roughness Rq = 11.48 ±3.32 nm and form accuracy of ±10 µm, for the purposes of illumination optics.

Terahertz Absorber with Graphene Enhanced Polymer Hemispheres Array.

We propose an original technique for the fabrication of terahertz (THz) metasurfaces comprising a 3D printed regular array of polymer hemispheres covered with a thin conductive layer. We demonstrate that the deposition of a thin metal layer onto polymer hemispheres suppresses the THz reflectivity to almost zero, while the frequency range of such a suppression can be considerably broadened by enhancing the structure with graphene. Scaling up of the proposed technique makes it possible to tailor the electromagnetic responses of metasurfaces and allows for the fabrication of various components of THz photonics.

Imaging-quality 3D-printed centimeter-scale lens.

Three-dimensional (3D) printing of imaging-quality optics has been challenging due to the tight tolerances on surface shape and roughness. We report on manufacturing such optics with Print optical Technology, which is based on modified ink-jet printing. We demonstrate for the first time a 3D-printed singlet lens with a surface profile deviation of ±500 nm within a 12-mm aperture diameter. Its RMS surface roughness is below 1 nm without surface polishing. The printed lens exhibits an imaging resolution of some 140 lp mm -1 at 100-mm focal length in the visible region.