Fiber laser refers to the use of rare earth element doped glass fiber as the gain medium of the laser, fiber laser can be developed on the basis of fiber amplifier. Under the action of pump light, high power density is easily formed in the fiber, resulting in the "population inversion" of the laser energy level of the laser working substance, and the laser oscillation output can be formed by adding a positive feedback loop (forming a resonant cavity) appropriately. Fiber lasers have a wide range of applications, including laser fiber communication, laser space long-distance communication, industrial shipbuilding, automobile manufacturing, laser engraving, laser marking, laser cutting, printing roller, metal and non-metal drilling/cutting/welding/(brazing, water quenching, cladding and deep welding), military national defense security, medical equipment and equipment, large-scale infrastructure, etc.

As a representative of the third generation laser technology, fiber laser has the following advantages:

1) Glass optical fiber has the advantages of low manufacturing cost, mature technology and small-sized words brought by the flexibility of optical fiber;

2) The glass fiber does not require strict phase matching for the incident pump light like the crystal, which is due to the non-uniform broadening of the absorption band caused by the glass matrix Stark splitting.

3) The optical fiber material has a very low volume to area ratio, fast heat dissipation, low loss, and low laser threshold.

4) The wavelength of the output laser is much, because the energy level of rare earth ions is very rich, and there are many kinds of rare earth ions in the machine.

5) good adjustability, thanks to the wide energy level of rare earth ions and the wide fluorescence spectrum of glass fiber.

6) Since there is no optical lens in the resonant cavity of the fiber laser, it has the advantages of no adjustment, no maintenance, and high stability, which is unmatched by traditional lasers.

7) fiber export, is the laser can easily be competent for a variety of multi-dimensional arbitrary space processing applications, so that the design of the mechanical system becomes very simple.

8) Competent for harsh working environment, with high tolerance to dust, oscillation, shock, humidity and temperature.

9) No thermoelectric cooling and water cooling are required, only simple air cooling is required.

10) With high electro-optical efficiency, its comprehensive electro-optical efficiency is as high as 20%, which can greatly save power consumption at work and save operating costs.