Laser-induced periodic structure formation in AlN ceramic

In this work, we show that nanosecond laser processing of aluminium nitride (AlN) ceramic by a Nd:YAG laser operated at the fundamental wavelength (1064 nm) leads to the formation of a conductive layer decorated by a ripples structure. The characteristic orientation of these structures is perpendicular to the incident laser polarization. The period of the ripples is lower than the laser wavelength, namely, about 830 nm. Such structuring is observed after processing both in air and in vacuum. We discuss the mechanism of periodic structures formation based on the dependence of the surface morphology on the laser pulse number and fluence applied and the results of a simulation using the finite-difference time-domain approach. These results can form the basis of fabricating aluminium micro- and nanostructures with potential applications in electronics and photonics as systems for UV plasmonics.