Hybrid curved nano-structured micro-optical elements

Abstract

Tailoring the spatial degree of freedom of light is an essential step towards the realization of advanced optical manipulation tools. A topical challenge consists of device miniaturization for improved performance and enhanced functionality at the micron scale. We demonstrate a novel approach that combines the additive three-dimensional (3D) structuring capability of laser polymerization and the subtractive subwavelength resolution patterning of focused ion beam lithography. As a case in point hybrid (dielectric/metallic) micro-optical elements that deliver a well-defined topological shaping of light are produced. Here we report on hybrid 3D binary spiral zone plates with unit and double topological charge. Their optical performances are compared to corresponding 2D counterparts both numerically and experimentally. Cooperative refractive capabilities without compromising topological beam shaping are shown. Realization of advanced designs where the dielectric architecture itself is endowed with singular properties is also discussed.

Tipping solutions: emerging 3D nano-fabrication/ -imaging technologies

“…micro-lenses [85] and milling high-aspect ratio holes [86]. Focusing of electrons and ions into tens-of-nanometer spot size still has a long depth of focus, e.g.…”

Large-scale high-numerical-aperture super-oscillatory lens fabricated by direct laser writing lithography

“…A combination of the DLW method and FIB lithography method has also been studied to produce nanostructured micro-optical elements. 22 As for SOLs, the line widths of SOL annular ring belts are typically in the range of hundreds of nanometres. Although previously reported SOLs have been mostly fabricated by the FIB/EBL method, it is not necessary to use such a high resolution fabrication method, especially for large-scale SOL masks, due to the aforementioned limitations.…”

All Femtosecond Optical Pump and X-Ray Probe: Holey-Axicon for Free Electron Laser

“…azimuthal angle. The spiral axicon is capable of generating higher order Bessel beams (HOBB) with a large focal depth and carries orbital angular momentum [89][90][91][92]. The images of the modulo-2π phase of the spiral axicon for L=0, 1, 2 and 3 are shown in Fig.…”