Laser hair removal device

Laser hair removal is based on the principle of Selective Photothermolysis, which precisely targets the melanin in the hair follicle through specific wavelength laser energy (such as 755nm, 810nm or 1064nm), destroying the core structure of hair growth, so as to achieve long-term hair reduction or even permanent suppression. The scientific process can be divided into the following key links:
Melanin absorption peak matching:
The melanin in the hair and hairball parts has a high absorption rate for specific wavelength laser (such as 810nm near-infrared light), and the laser wavelength avoids the absorption peak of other skin color bases such as hemoglobin and water, minimizing the damage to the surrounding tissue.
Photothermal effect:
After absorbing light energy, melanin turns into heat energy, and the local temperature rises to more than 70℃ within millisecond pulse time, directly damaging the activity of Hair Stem Cells (HFSCs) and Dermal Papilla Cells (DPC). Stop the hair growth cycle.

Growth follicle sensitivity:
Hair follicles that are only in the first Phase of the Anagen Phase contain enough melanin to effectively absorb laser energy. Because human hair is at different stages of growth, it is necessary to cover all follicle active periods through multiple treatments (usually 4-6 times).
Hair follicle stem cell destruction:
The laser energy damages the stem cells in the hair follicle prolongation area through thermal diffusion, preventing the regeneration ability of broken hair and ensuring the durability of the effect (clinical validation: 75-90% irreversible hair reduction within 6 months).
Wavelength selection:
Short wavelength (755nm) : for dark-haired and light-skinned people;
Long wavelength (1064nm Nd:YAG) : Deeper penetration, suitable for dark skin (Fitzpatrick IV-VI type), reducing the risk of competitive absorption of epidermal melanin.
Pulse width and cooling system:
Pulse width (1-100ms) matches hair follicle thermal relaxation time to avoid epidermal burn;
Dynamic cooling technologies (such as sapphire contact cooling, cold air injection) protect the skin in real time and improve treatment tolerance.
Histological evidence:
Follicle vacuolation, fibrosis and other structural damage occurred after treatment, and hair follicle atrophy could be observed by dermoscopy or biopsy.
Maintenance cycle:
1-2 years after treatment, the hair density is reduced by an average of 80%-90%, and the residual hair is mostly soft and soft, and the "optical hair removal" state can be maintained by 1-2 consolidation treatments per year.