Higher fluencies can be used with which type of spot size?

The correct understanding is that higher fluencies are typically used with smaller spot sizes. This relationship is due to the physics of laser-tissue interaction. When a laser beam is focused to a smaller spot size, the energy delivered per unit area increases, resulting in higher fluency. Higher fluency allows for more precise treatment while ensuring that adequate energy is delivered to achieve desired outcomes.

In the context of laser treatments, smaller spot sizes tend to enhance the effectiveness of procedures that require more concentrated energy, such as targeting specific areas of skin or lesions. Although larger spot sizes can also utilize high fluencies, the energy is distributed over a wider area, which might not achieve the same intensity necessary for certain applications. Therefore, smaller spot sizes are the best match for utilizing high fluences effectively in various laser treatments.