What are the temporal intensities from largest to smallest?

• A. Itp, Imax, Ipa, Ita
• B. Ita, Ipa, Imax, Itp
• C. Ipa, Itp, Imax, Ita
• D. Imax, Ita, Itp, Ipa

Answer: (A)

In a pulsed situation, you can describe intensity at different time scales, and each step toward averaging lowers the value. The highest value is the temporal peak intensity, which is the exact maximum instantaneous brightness during the pulse. As you move to metrics that summarize over time rather than capture the single instant, you get smaller values: the maximum instantaneous (over short windows) is less than the true peak because you're smoothing around the peak. The pulse-average intensity averages only over the on-time of the pulse, which typically yields a smaller number than the peak because it includes times when the pulse is not at peak. Finally, the temporal-average intensity averages over the entire cycle, including off times, so it’s the smallest.

Therefore, the temporal intensities from largest to smallest are: temporal peak intensity, then the maximum instantaneous intensity, then pulse-average intensity, and then temporal-average intensity.