Laser nano-manufacturing technology and applications towards optical functional nanostructures and devices

The rapid development of nanotechnology, such as microelectromechanical systems (MEMS), microelectronics and nanophotonics, has led to the emerging attentions in achieving functional optoelectronic structures and/or metamaterials at micro and nanoscale resolution. Multiphoton absorption nanofabrication has demonstrated its great potential for applications in preparation of complex three-dimensional (3D) nanostructures at micro and nanoscales. Here, we report new laser nano-manufacturing approaches, multiphoton polymerization (MPP) and multiphoton photoreduction (MPR), to fabricate optical functional nanostructures. The luminescent nanostructures have been created by the in situ synthesis of semiconductor nanoparticles in a polymer matrix with fine size control and the MPP process. This represents the first successful fabrication of multicolor 3D microstructures of semiconductor-polymer nanocomposites using a laser microstereolithography technique. Ultra-thin chiral metasurfaces with giant broadband optical activity in the infrared wavelength have been realized. The chiral metasurfaces consisting of periodic hole arrays of complementary asymmetric split ring resonators (SRRs) are fabricated by MPP. Enhanced transmission with strong polarization conversion up to 97% is observed owing to the chiral surface plasmons from mirror symmetry broken. Furthermore, a planar electromagnetic metamaterial made of U-shaped SRRs has been fabricated by the MPR in the aqueous solution of gold ions with the assistance of ionic liquid (IL). The measured spectra are consistent with theoretical predictions for the metamaterial fabricated by laser direct writing technique. The proposed laser nano-manufacturing technique would open up new avenues for the fabrication and application of micro- and nanoscale devices in photonics, electronics, and biotechnology.