Direct laser coding of plasmonic nanostructures for data storage applications

We demonstrate the realization of desired gold plasmonic nanostructures by direct laser writing (DLW) method employing a continuous-wave 532 nm laser. By moving the laser focusing spot of the DLW system, the gold nanoparticles (NPs) are formed following the laser moving path. The plasmonic patterns composing of gold NPs enable a lot of applications, such as direct text writing and inverse text writing at micro scale, bar code and QR code to store the messages, binary recordings as compared to standard CDs and DVDs. Furthermore, by controlling the laser intensity and/or the exposure time, the NPs size was changed resulting in different plasmonic colors, and offering a new method to nanoprint with color.