Spectral Power Distribution

aka SPD

definition the term spectral power distribution can refer to the concentration, as a function of wavelength, of any radiometric or photometric quantity --- Wikipedia

spectral power distributions can be used to represent colors in a plot where the horizontal axis represents wavelength and the vertical axis represents luminous intensity

examples

--- https://www.energy.gov/sites/prod/files/2016/11/f34/royer_spectral-power-dist_denver2016.pdf