Formation of microbumps and nanojets on gold targets by femtosecond laser pulses

Femtosecond laser-induced sub-wavelength microstructuring of a thin gold layer coated onto a quartz glass substrate is investigated. Formation of microbumps (microbubbles) and nanojets under single pulse laser irradiation is observed. Discussion of these effects and demonstration of their dependencies on the laser pulse energy and gold layer thickness are presented.