An equivalent method of multi-beam laser interference lithography for 2D plasmonic crystals fabrication

We proposed an approach to fabricate two-dimensional (2D) plasmonic crystals based on equivalent multi-beam interference lithography. With a self-designed truncated hexagonal pyramid, three sub-wavelength structures were demonstrated and characterized, and the corresponding simulation was also carried out and well fitting. Further, the plasmonic Bloch waves (PBWs)–mediated fluorescence radiation was investigated and the wavelength-dependent fluorescence directional emission was observed. This work might provide a simple, flexible and low-cost way to achieve complex large-scale plasmonic crystals with nanoscale features for some practical applications, such as surface-enhanced Raman scattering (SERS) substrates, photovoltaic devices and biological chips.