What is meant by 'fluence' in laser applications?

Fluence in laser applications refers specifically to the amount of energy delivered per unit area. It is a crucial factor in determining the effectiveness of laser treatments and procedures. Fluence is typically expressed in joules per square centimeter (J/cm²). This measurement indicates how much energy is applied to a particular area during a laser treatment, which can influence the treatment's efficacy and safety.

Understanding fluence is essential because it helps practitioners adjust the laser settings to achieve the desired outcomes, whether for aesthetic procedures, medical treatments, or industrial applications. Correctly calculating and applying fluence ensures that the laser achieves the necessary thermal effects to target tissues or materials without causing damage to surrounding areas.

In this context, the other options do not encapsulate the precise meaning of fluence; while the distance from the laser source, duration of the laser pulse, and intensity of the laser beam are relevant to laser physics, they describe different aspects of laser application rather than the specific measurement of energy per area that fluence represents.