Laser photonic nanojets triggered thermoplasmonic micro/nanofabrication of polymer materials for enhanced resolution

Micro/nanofabrication of polymer materials is of interest for micro/nanofluidic systems. Due to the optical diffraction limit, it remains a challenge to achieve nanoscale resolution fabrication using an ordinary continuous-wave laser system. In this study, we therefore propose a laser photonic nanojet-based micro/nanofabrication method for polymer materials using a low-power and low-cost continuous-wave laser. The photonic nanojets were produced using glass microspheres. Moreover, a thermoplasmonic effect was employed by depositing a gold layer beneath the polymer films. By applying the photonic nanojet triggered thermoplasmonics, sub-micrometer surface structures, as well as their arrays, were fabricated with a laser power threshold value down to 10 mW. The influences of the microsphere diameters, and thicknesses of gold layers and polymer films on the fabricated microstructures were systematically investigated, which aligns well with the finite-difference time-domain simulation results.

Automated summary

A method for micro/nanofabrication of polymer materials using a low-power continuous-wave laser based on laser photonic nanojets was proposed in this study. The use of photonic nanojets triggered thermoplasmonics allowed for the fabrication of sub-micrometer surface structures with a laser power threshold value down to 10 mW. The effects of microsphere diameters, gold layer thicknesses, and polymer film thicknesses on the fabricated microstructures were systematically investigated and aligned with simulation results.