Although the superresolution effect obtained for circular polarized light is only 9%
when the NA of the lens is 0.85, which corresponds to a decrease of 18% in beam
area or a 22% increase in disk capacity; this superresolution ratio may increase to
around 20% for lower numerical apertures such as NA = 0.65, which corresponds
to a 36% decrease in beam area, or around a 50% increase in disk capacity