"What's the difference between different wavelengths of laser acting on the skin?" In fact, different wavelengths, different penetration depths and different absorption targets, so the effects they can achieve are completely different.

I. Basic principles

In fact, skin is like a "layered filter", with epidermis outside and dermis and subcutaneous tissue inside. Lasers with different wavelengths enter, some only work in the epidermis, and some can penetrate deep into the dermis. The energy of laser will be absorbed by specific "color groups", such as melanin, hemoglobin and water.

Laser with short wavelength (for example, between 400 and 600 nm) is mainly absorbed by melanin, which is suitable for freckle removal, mole removal and whitening.

Medium wavelength (600~1000nm) can penetrate into the dermis and act on hair follicles, blood vessels and other tissues, which are often used for hair removal and red blood silk removal.

Longer wavelengths (above 1000nm) are mainly absorbed by water and used for skin rejuvenation, firming or ablation.

Second, common wavelengths and their functions

532nm (green light)

The energy in this band is mainly absorbed by melanin and hemoglobin, which is suitable for superficial skin problems.

Such as freckles, sunburn, coffee spots, vascular nevus, small red blood, etc.

However, the penetration is relatively shallow, only about 0.5 mm, so it is more suitable for epidermal treatment.

laser

635nm (red light)

This band is often used for "skin repair and cell activation".

Red light can promote collagen production, stimulate cell metabolism and contribute to wound healing.

Many beauty instruments, red light physiotherapy instruments, and medical art post-repair instruments use this band.

Its energy is mild, it does not destroy the skin structure, but it can promote recovery.

755nm (emerald laser)

This band has moderate penetration depth and strong absorption of melanin, and is often used for depilation, freckle removal and skin rejuvenation.

Especially in the field of medical beauty hair removal, it is one of the wavelengths commonly used in high-end instruments.

It can effectively penetrate the epidermis and reach the hair follicle, but it doesn't hurt the surrounding tissues too much.

808nm (infrared light)

This is the most common hair removal wavelength, and it is also one of the mainstream bands of laser diodes.

It has stable energy and deep penetration, and can directly reach the root of hair follicle, so that hair follicle naturally dies after absorbing heat energy.

Moreover, this band is less irritating to the skin and has high safety, so many household hair removal instruments also use it.

980nm

This kind of laser has a strong absorption of hemoglobin and can be used to seal blood vessels, remove red blood and stop bleeding.

Many doctors use it for "treatment of facial vascular diseases", such as red blood and spider nevus on the face.

It can also be used as a hemostatic knife or coagulation tissue in medicine, so it has a wide range of medical uses.

laser

1064nm

The penetration depth is stronger, and it can reach the dermis or even subcutaneous tissue.

Suitable for the treatment of deep spots, pigmentation, tattoos, moles and wrinkles.

Because it can penetrate deeply, 1064nm laser is very popular in Asian skin, and its energy is concentrated and it is not easy to turn black.