The best way of supplying a broad band, stable light pulse with a flat time profile is by using a xenon arc lamp operated by adding a “super current pulse” to the low current simmer supply. A pulsed xenon lamp exhibits a significant increase in the emitted photon flux during the period of the pulse, compared with the photon flux from the same lamp in steady state operation over the equivalent time period. During pulsed operation, the colour temperature of the arc is dramatically increased over its steady state equivalent and as a result, the emission profile is shifted towards the UV and the spectrum is less structured. The LP980 contains a built-in lamp pulser with particular emphasis on pulse flatness, reproducibility and minimum ripple.