Let you instantly understand the four characteristics of laser

Since the invention of laser, with its own excellent characteristics, it has been widely used in the fields of industrial processing, medical beauty, scientific research and so on. The laser has four main characteristics: high brightness, good directivity, good monochromaticity and high coherence. These properties are related to each other, so that the laser can be applied to different scenes.

High brightness of laser

Laser with high brightness is mainly due to its highly focused beam. The high brightness of laser is also the embodiment of its high energy concentration. After the lens is focused, a high temperature of thousands of degrees or even tens of thousands of degrees can be formed near the focus, which makes it able to process almost all materials.

High energy concentration is a very important characteristic of laser. Because of its advantages, it can be widely used in the fields of industrial processing and medical treatment.

Monochromaticity

The color of light is determined by the wavelength of light, and light has a certain wavelength range. The narrower the wavelength range, the better the monochromaticity. For ordinary light source, because the spectral line width is larger and the frequency range is too wide, the color displayed will be more miscellaneous.

Although, compared with the ordinary light source, the spectral line width of laser is much narrower. However, the linewidth of laser is restricted by many factors, and it is almost impossible to reach the theoretical level. For example, the change of temperature, a little vibration of laser, the air flow in its volume optical device, and the external pump and other factors will lead to the instability of resonance frequency, which will cause the performance degradation.

Good direction

The light from ordinary light source propagates along all directions, with a large divergence angle. In contrast, the divergence angle of laser is very small, and it is almost emitted in parallel direction. The light emitted by laser is a kind of polarized light with fixed direction. A simple case can express this intuitively: the laser does not refract the water.

Among all kinds of lasers, gas laser is the most prominent in directivity, followed by solid-state laser, and semiconductor laser is slightly inferior in this aspect.

Good coherence

The light wave is composed of numerous photons. The photons emitted from the laser are consistent in wavelength, frequency and polarization direction due to the resonance principle, which makes it have a very strong interference force. We also call laser coherent light. It is because the coherence of laser is much stronger than that of ordinary light source.

Using laser as the light source of hologram is also the characteristic of good coherence.