Which of the following terms relates to laser energy's measurement?

The measurement of laser energy is most commonly expressed in joules (J), which is the standard unit of energy in the International System of Units (SI). This measurement quantifies the amount of energy produced or delivered by the laser over a specific period of time or emission. Joules help professionals quantify the energy output of the laser during procedures, which is essential for ensuring safety and effectiveness.

Fluence, while related to laser energy, specifically describes the energy delivered per unit area and is typically expressed in joules per square centimeter (J/cm²). This parameter focuses on how concentrated the energy is at the point of application rather than the total energy delivered.

Wavelength measures the distance between successive peaks of a laser's light wave and influences the laser's interactions with skin and tissue but does not directly indicate the energy output.

Pulse width refers to the duration of time over which the laser emits energy in a single pulse. While important for determining the energy delivery rate and tissue interaction, it does not measure energy itself.

Thus, joules is the most direct and appropriate term for measuring the energy output of a laser.