Fluence is expressed in what units?

Fluence is defined as the energy per unit area delivered by a laser beam and is commonly expressed in joules per square centimeter (J/cm²). This measurement indicates how much energy is being concentrated over a specific area during laser treatment or application, which is crucial for determining the effectiveness and safety of laser procedures in various medical and industrial contexts. Understanding fluence is vital for practitioners to ensure they are applying the correct amount of energy for effective treatment without causing harm to the surrounding tissues or materials. Thus, joules as a unit of energy is the correct choice for expressing fluence.