Views:5 Author:Site Editor Publish Time: 2021-01-23 Origin:Site
Structure of fiber lasers
There are three basic conditions needed for the generation of laser signals: population inversion, optical feedback, and laser threshold. The laser is therefore composed of a working material, a source of pumps, and a resonant cavity. The fundamental fiber laser structure is as follows. The gain fiber is the gain medium that emits photons; the pump light acts as external energy to allow the gain medium, which is the source of the pump, to achieve population inversion; the optical resonant cavity consists of two mirrors, the purpose is to get input from photons and amplify them in the working medium.The pumped light reaches the fiber of gain and is absorbed, which in turn reverses the amount of particles of the energy level in the medium of gain. A laser oscillation between the two mirrors will be produced when the gain in the resonant cavity is greater than the loss, resulting in the output of a laser signal.
Cutting features of fiber
The waveguide arrangement of the fiber specifies that a single transverse mode output is simple to obtain by the fiber laser and is not influenced by external factors and can achieve high laser output brightness.
2. High efficiency
Fiber lasers can achieve high light conversion efficiency by selecting semiconductor lasers with matching emission wavelengths and absorption characteristics of doped rare earth elements as pump sources. For Ytterbium-doped high-power fiber lasers, 915 nm or 975 nm semiconductor lasers are generally selected, which have a longer fluorescence lifetime and can effectively store energy to achieve high-power operation. The overall electro-optical efficiency of commercial fiber lasers is as high as 25%-50%, which is conducive to cost reduction, energy saving and environmental protection.
3. Good heat dissipation characteristics
The fiber laser uses a slender rare-earth-doped fiber as the laser gain medium, and its surface area to volume ratio is very large. About 1000 times that of solid bulk lasers, it has a natural advantage in heat dissipation. There is no need for special cooling of the optical fiber in low-to-medium power situations, and water-cooled heat dissipation is used in high-power situations, which can also effectively avoid the drop in beam quality and efficiency caused by thermal effects in solid-state lasers.
4. Compact structure and high reliability
Because the fiber laser uses a small and flexible fiber as the laser gain medium, it is beneficial to compress the volume and save the cost. The pump source is also a semiconductor laser that is small in size and easy to modularize. Commercial products generally can be output with pigtails, combined with fiberized devices such as fiber Bragg gratings. As long as these devices are fused to each other, the full fiber can be realized. It has high disturbance immunity and high stability, which can save maintenance time and cost.
Fiber laser advantages
As a representative of the third-generation laser technology, fiber lasers have 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 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.
3. 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.
4. Tunability: Due to the wide energy level of rare earth ions and the wide fluorescence spectrum of glass fiber.
5. Since there is no optical lens in the resonant cavity of the fiber laser, it has the advantages of adjustment-free, maintenance-free and high stability, which is unmatched by traditional lasers.
6. The optical fiber is exported, so that the laser can be easily qualified for various multi-dimensional and arbitrary space processing applications, making the design of the mechanical system very simple.
Dato Laser is committed to the field of laser cutting. Since its establishment, it has continued to grow and promote high-tech and high-quality product concepts. It has been continuously engaged in steel metallurgy, aerospace, automotive industry, computer manufacturing, military electronics, machinery manufacturing, hardware tools, Intensive cultivation in industries such as integrated circuits.