Nanostructured Metal Substrates Fabrication for Surface Enhanced Fluorescence Using the Nanosecond Speckle-Modulated Laser Pulses

Nanosecond speckle-modulated laser pulses were applied to fabricate nanotextured metal substrates for surface enhanced fluorescence (SEF) applications. The speckle-modulated patterns obtained by passing the laser nanosecond pulse through the simplest diffusive object were found suitable for fast large-scale texturing of metal films with micron-sized structures - nanojets, nanobumps and submicron through holes, previous reported only for single-shot nanoablation with tightly focused beams. The optimal regime for pattering the mm-scale areas of Au films with nanojets with an averaged recording density of 105 nanojets per square millimeter were determined and realized. The fabricated nanotextured Au substrates demonstrate spatially uniform SEF signal from the Rhodamine 6G organic dye with averaged 5-fold enhancement factor being compared with unmodified Au surface.