Which term defines the maximum instantaneous power density during the on-time of a pulsed emitter?

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

Answer: (C)

During a pulsed emission, power arrives in bursts and reaches a highest value while the emitter is ON. That highest, momentary power density is called the peak power. It represents the maximum instantaneous power during the on-time, independent of how long the pulse lasts or how often it repeats. In contrast, the average power over a full cycle accounts for the off-times and is given by P_avg = P_peak × duty cycle, where the duty cycle is the fraction of time the emitter is ON. Exposure duration simply tells how long the exposure occurs and does not define the power level. So the term describing the maximum instantaneous power density during the on-time is peak power.