Which term is used to describe the maximum power density during the on-time of a pulsed emitter?

• A. Duty Factor
• B. Peak Power
• C. Average Power
• D. Exposure Duration

Answer: (B)

In pulsed emission, the important distinction is between the instantaneous power reached during the on-time and the average power over the whole cycle. The maximum power density that occurs during the on interval is called the peak power. This is the highest value the system achieves, observed right when the pulse is on.

The duty factor, by contrast, is simply the fraction of time the pulse is on, so it tells you how long the pulse lasts relative to the total period but not how large the pulse itself is. The average power is the overall power averaged across the entire cycle, which, for a simple pulsed waveform, depends on both how tall the pulse is (the peak) and how long it lasts (the duty factor). Exposure duration refers to how long the exposure occurs, not the peak intensity of the pulse.