The phase method laser rangefinder detects the distance by detecting the phase difference between the emitted light and the reflected light when they propagate in space. The laser rangefinder is light in weight, small in size, simple in operation, fast and accurate, and its error is only one-fifth to one-hundredth of that of other optical rangefinders. In the right figure, there are typical phase method rangefinders and pulse method rangefinders.

As the price of laser rangefinders has been continuously reduced, laser rangefinders have gradually been used in industry. At home and abroad, a number of new micro-distance meters with the advantages of fast ranging, small size and reliable performance have emerged, which can be widely used in industrial measurement and control, mines, ports and other fields.