Fiber lasers refer to lasers that use rare-earth-doped glass fibers as gain media. Fiber lasers can be developed on the basis of fiber amplifiers: high power density is easily formed in the fiber under the action of pump light, resulting in laser working material. The energy level "number inversion" can form laser oscillation output when a positive feedback loop (form a resonant cavity) is properly added.
As a representative of the third-generation laser technology, it has the following advantages:
(1) The advantages of miniaturization and intensiveness brought about by the low manufacturing cost of glass optical fiber, mature technology and the flexibility of optical fiber;
(2) The glass fiber does not need to have a strict phase matching for the incident pump light like crystals. This is due to the non-uniform broadening caused by the Stark splitting of the glass matrix, resulting in a wider absorption band;
(3) The glass material has a very low volume-to-area ratio, fast heat dissipation and low loss, so the conversion efficiency is high and the laser threshold is low;
(4) The output laser has many wavelengths: this is because the energy levels of rare earth ions are very rich and there are so many kinds of rare earth ions;
(5) Tunability: Due to the wide energy level of rare earth ions and the wide fluorescence spectrum of glass fiber.
(6) Because there is no optical lens in the resonant cavity of fiber laser, it has the advantages of adjustment-free, maintenance-free and high stability, which is unmatched by traditional lasers.
(7) The fiber export makes the laser capable of various multi-dimensional and arbitrary space processing applications easily, making the design of the mechanical system very simple.
(8) Competent in harsh working environment, with high tolerance to dust, shock, impact, humidity and temperature.
(9) No need for thermoelectric cooling and water cooling, just simple air cooling.
(10) High electro-optical efficiency: The comprehensive electro-optical efficiency is as high as 20%, which greatly saves power consumption during work and saves operating costs.
(11) The high-power, commercial fiber laser is six kilowatts.