What is wavelength penetration depth?
Wavelength penetration depth refers to how deeply different light wavelengths can travel into biological tissues.
In hair restoration therapy, red light at around 650 nm wavelength penetrates the epidermis and dermis layers effectively, reaching hair follicle structures without damaging deeper tissues.
Optimizing wavelength penetration depth ensures that therapeutic light energy reaches the intended targets — the scalp and follicular mitochondria — maximizing red light therapy effectiveness for hair growth stimulation.
Related terms
Therapeutic window
Light & Technology
The therapeutic window in light therapy refers to the optimal dosage range (wavelength, intensity, and duration) that produces biological benefits without causing harm.
Intense Pulsed Light (IPL)
Light & Technology
Intense Pulsed Light (IPL) is a broad-spectrum light therapy that emits multiple wavelengths.
660 nm wavelength
Light & Technology
The 660 nm wavelength refers to a specific red light frequency commonly used in therapeutic devices to stimulate biological processes.
Low-level laser therapy (LLLT)
Light & Technology
Low-level laser therapy (LLLT) is a treatment that uses low-intensity lasers or LEDs to stimulate cellular activity without heating tissues.
