where p is the mean first-neighbor particle distance, R is the radius of the plasmonic NP, and D is the characteristic size of the illuminated area. For a Gaussian illumination, D is the width-halfmaximum (FWHM) of the beam. For example, a value of  = 0.1 under CW illumination indicates that ΔTglobal is 10 times ΔTnano.