① solid-state laser; ② gas laser; ③ liquid laser; ④ Semiconductor laser.

The appearance of cosmetic laser provides a new technical treatment method for plastic surgery, and also solves many problems that cannot be solved by previous treatment methods. However, most cosmetic laser equipment only entered the medical industry in China in recent years because of its complicated technology and high price.

Laser realizes its function by interacting with tissues. According to what kind of energy the tissue converts the laser into, the laser is divided into;

① Photothermal effect: tissues convert the light energy of laser into heat energy, and different tissues have different absorption coefficients, so the laser with a specific wavelength can be absorbed by some specific tissues, which is the fundamental reason for choosing high laser for fine cutting, hemostasis and facial wrinkle removal.

(2) light burst effect: pulsed laser can produce shock wave with strong impact force, which makes tissues burst and smash, such as laser destroying pigment particles;

(3) Photochemical effect: tissue converts laser into chemical energy, resulting in chemical decomposition. Such as ArF excimer laser to correct corneal deformation;

④ Photodynamic effect: It is mainly used to treat tumors.

2, laser beauty according to the purpose can be divided into:

(1) Laser removes various pigments from facial skin, such as melanin (nevus, tattoo) and red pigment (hemangioma);

(2) Laser removal of skin defects, such as moles, warts, papules, vegetation and benign tumors;

(3) permanent removal of excess body hair by laser;

(4) removing facial wrinkles by laser;

(5) Using laser knife instead of scalpel to perform fine, minimally invasive and bloodless plastic surgery.