Surface Plasmon Polaritons for Micro and Nano-texturing of Metal Surfaces

Surface Plasmon Polaritons (SPPs) have been known since the late 1950s with the work of Richie [1]. Today most research with these surface waves is aimed at production of subwavelength components in an attempt to merge the subjects of electronics and photonics on a nanometer scale. However, the features produced by SPPs could have uses in direct engineering applications due to their surface texturing capabilities, an area that is less exploited. The presented work is a demonstration of the production of SPP features by two picosecond pulsed fibre laser systems for the surface texturing of M42 High Speed Steel (HSS) (approximate composition by % wt; 1.1% C, 0.28% Mn, 0.4% Si, 3.88% Cr, 0.30%Max Ni, 9.5% Mo, 1.5% W, 1.15% V, 8.25% Co) and Ti-6Al-4V. Use of these laser systems allowed for the production of SPP patterns at high repetition rates (200kHz). Manipulation of the laser polarization allowed for the writing of features in a wide range of orientations allowing for greater control over the patterns produced. Writing, overwriting, erasing and rewriting of SPP features is demonstrated. The effect of these patterns on the water contact angle of HSS and Ti-6Al-4V was examined, and was found to reduce this value significantly in both cases.