Skin & Hair
This layer is the body’s outer protective covering and is avascular.
What is the epidermis?
This is the distance from peak to peak of a light wave, measured in nanometers.
What is wavelength?
This light source is not a true laser and uses a range of wavelengths plus filters.
What is IPL (Intense Pulsed Light)?
This hair growth stage is required for laser hair reduction to effectively damage the follicle.
What is the anagen phase?
This basal layer of the epidermis contains melanocytes and is where new cells divide.
What is the stratum germinativum?
This non‑harmful category of radiation is used by cosmetic lasers.
What is non‑ionizing radiation?
IPL devices typically span this approximate wavelength range, from visible into near infrared.
What is about 400–1500 nm?
When charting, this term describes the perifollicular swelling seen as a normal response after LHR.
What is perifollicular edema (PFE)?
This hair type is thick and coarse compared with vellus and intermediate hair.
What is terminal hair?
This tissue interaction where the chromophore takes in light and converts it to heat. This is the goal in laser treatments.
What is absorption?
The measurement of heat/energy delivered per square centimeter in a laser pulse.
What is fluence (J/cm²)?
These two wavelengths can typically be used safely across all Fitzpatrick types for LHR when settings are appropriate.
What are 1064 nm (Nd:YAG) and 800–855 nm (diode)?