Laser, or “leizha,” in Chinese is the phonetic translation of the English word “LASER,” which stands for Light Amplification by Stimulated Emission of Radiation. Intense pulsed light (IPL) is a mixed polychromatic light, similar to rainbow light, which is why it is called “color light”. Laser and IPL are both light, but what are the differences between the two? First, let’s discuss laser physics.

Laser has the following characteristics:

1. Laser is monochromatic, which means it only produces one wavelength of light in the entire generation mechanism. This is different from ordinary light, such as sunlight and lamp light, which are composed of multiple wavelengths of light and resemble white light.
2. Laser is coherent, meaning that all photons have the same coherence and polarization, and when they are superimposed, they produce a very high intensity. The coherence and polarization of light in daily life are random, and compared to lasers, these lights are much weaker.
3. Laser beams are very narrow and highly concentrated, which gives them a strong power. In contrast, lamp light is scattered in all directions, so its intensity is low.

Because of these characteristics, laser energy is stronger and has considerable destructive power, making it effective in improving deep-seated skin problems. Laser has a wide range of applications and various types, and different types of lasers can target different skin problems, such as freckles, moles, scars, skin rejuvenation, and hair removal, and more.

IPL, on the other hand, is a type of mixed polychromatic light and does not have the characteristics of laser. Because it has multiple wavelengths of light, it’s like diversified investments. Therefore, IPL can treat different skin problems, but the effect is more difficult to control and not all skin problems are suitable for IPL.

Both IPL and laser release high thermal energy and improper use can cause burns, causing blisters, scabs, and even scarring. The side effects of IPL are greater than those of lasers. The safety margin of IPL, which releases high thermal energy, is narrow. If the thermal energy is slightly higher, the chance of burns increases. If there is a lack of operating experience, problems can arise. New laser equipment has different freezing technology to protect the epidermal layer. In contrast, IPL uses frozen gel, the freezing effect may not be ideal, and it is more prone to burns.

Whether IPL or laser, both release high thermal energy, and their use should be supervised by a doctor. The government is currently discussing how to legislate and regulate medical cosmetic procedures to ensure consumer safety.