What should a practitioner do to achieve deeper laser penetration?

To achieve deeper laser penetration, changing to a bigger spot size is effective because it allows for a larger area of tissue to be treated simultaneously, which can result in a more uniform energy distribution. A larger spot size can also reduce the thermal cooling effect of the surrounding tissue, allowing for better energy absorption at greater depths.

The other options do not facilitate deeper penetration as effectively. Using a higher frequency typically affects the absorption characteristics of the tissues rather than increasing penetration depth. Reducing the energy output would diminish the energy reaching the deeper tissues, potentially resulting in lesser effectiveness. Increasing the duration of exposure might allow more energy to be delivered over time, but it does not necessarily improve penetration depth in comparison to simply increasing the spot size, which simultaneously enhances coverage and energy delivery to deeper layers.