The energy associated with an electromagnetic wave, in its simplest form, is given by the relation: $$ E = h\nu $$ Where $h$ is Planck's constant. However, this energy relates to a definite frequency. In an electromagnetic impulse, there is a frequency band contained in the wave packet. Does this mean that an impulse also contains a band of energy values? Something along the lines of: $$ \Delta E = h\Delta\nu $$ The most intuitive idea of this could be a superposition of (analytically possible, maybe not so physically accurate) photons, each carrying its own energy?