We investigate the variations that occur with changes in the number of layers and with the use of the assist beam main and assist beam energy on the morphology of HfO2/SiO2 quarter wave stacks deposited by dual ion beam sputtering. We show how the addition of sequential HfO2/SiO2 bilayers, up to eight, affects the surface roughness and micro-crystallinity of the top HfO2 layer. We also show that use of the assist source significantly smooths the surface while simultaneously reducing microcrystallinity. The HfO2/SiO2 structures are very robust and can withstand fluences in excess of 3 J/cm2 generated by 1ps pulses from a chirped amplified Ti:Sapphire laser.© (2007) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.