What are the main characteristics of laser compared with ordinary light source?

Compared with ordinary light, laser has four characteristics:

(1) high brightness

Because of its strong emission ability and high energy concentration, the brightness of laser is very high, which is hundreds of millions of times higher than that of ordinary light sources and tens of billions of times higher than that of the sun surface. Brightness is an important index to measure the quality of a light source. If the medium-intensity laser beam converges, it can produce high temperature of thousands to tens of thousands of degrees at the focus.

(2) Good directionality

The divergence angle after laser emission is very small. The laser emits 20 kilometers, and the spot diameter is only 20-30 cm. The laser hit the moon at 380,000 kilometers, and the spot diameter was less than 2 kilometers.

(3) Good monochromaticity

The color of light is determined by the different wavelengths of light, and different colors are reflected by the different effects of light with different wavelengths on human vision. Lasers have basically the same wavelength, narrow spectral line width, pure color and good monochromaticity. Because of this characteristic, laser is widely used in communication technology.

(4) Good consistency

Coherence is the * * * property of all waves, but due to the different quality of various light waves, its coherence is also different. Ordinary light is spontaneous radiation and will not cause interference. Laser is different from ordinary light source, it is stimulated radiation with strong coherence, so it is called coherent light.