CLT Laser Modalities & Applications 3

Question 1

According to the theory of selective photothermolysis, the pulse duration should be:

Accepted Answer

Equal to or shorter than the thermal relaxation time of the target

Answer

Pulse duration at or below the target's thermal relaxation time confines heat to the chromophore, preventing collateral tissue damage.

Question 2

Which parameter describes the total energy delivered per unit area during a laser treatment?

Accepted Answer

Fluence (J/cm²)

Answer

Fluence, measured in joules per square centimeter, represents the total energy deposited per unit area and is a key determinant of treatment efficacy.

Question 3

Increasing the spot size of a laser beam while maintaining the same fluence will generally:

Accepted Answer

Increase depth of penetration due to reduced scatter effects

Answer

Larger spot sizes reduce lateral scatter at the beam edges, allowing photons to penetrate deeper into tissue at equivalent fluences.

Question 4

Q-switching in laser technology achieves extremely short, high-peak-power pulses primarily for:

Accepted Answer

Tattoo and pigmented lesion removal via photomechanical effect

Answer

Q-switched lasers generate nanosecond pulses with extreme peak powers that shatter pigment particles via photomechanical (acoustic) waves rather than thermal heating.

Question 5

A laser's thermal relaxation time is primarily determined by:

Accepted Answer

The size of the target chromophore

Answer

Thermal relaxation time scales with the square of the target's diameter, so larger targets (like hair follicles) have longer thermal relaxation times than smaller targets (like melanosomes).

(CLT) Certified Laser Technician Practice Test

(CLT) Certified Laser Technician Practice Test

CLT Laser Modalities & Applications 3