Fluence in laser terms is measured in what units?

Fluence in laser terms refers to the energy delivered per unit area, and it is typically expressed in joules per square centimeter (J/cm²). Joules represent the amount of energy transferred, making them the appropriate unit when discussing fluence because fluence directly relates to the energy density of the laser beam that is being applied to the tissue.

When considering other units: meters are a measure of distance and do not relate to energy or laser application; watts measure power (energy per unit time), which does not convey the relationship of energy to area; and millijoules, which is a smaller unit of joules, could also be used to express energy but is not the standard unit for defining fluence as joules are more commonly recognized in this context. Thus, joules are the unit that accurately embodies the concept of fluence as energy spread over an area, making it the correct choice.