In gas discharge lamps, such as flashlamps, current density plays an important role in the output spectrum produced.

Its output spectrum peaks at 410 nm, which is violet.

Adjustments routinely include changes in output volume and output spectra of individual speakers.

The LED output spectrum is additionally very cold (blue) compared to the warm (yellow/red) of the incandescent.

A deuterium lamp uses a tungsten filament and anode placed on opposite sides of a nickel box structure designed to produce the best output spectrum.

The output spectrum consists of a continuous spectrum of X-rays, with additional sharp peaks at certain energies (see graph on right).

The output spectrum of a flashlamp is primarily a product of its current density.

The FFT process applies windowing techniques to improve the output spectrum due to producing less side lobes.

This leads naturally to definition of the coherent output spectrum:

The effect on the output spectrum is negligible, but the effect on efficiency is great.