Among the different types of lasers, fiber lasers are the fast-growing and prevalent type of laser due to their meaningful advantages: flexibility, efficiency, and high performance. Most advances in fiber laser technology focused on ytterbium (Yb)-doped fibers operating around 1 micron(µm). Two factors influence the success of these lasers. First, the materials can be very efficient because this materials system has a low quantum defect. Second, there are many high-brightness pump sources at 915–975 nm. These factors allow high-efficiency operation and low thermal loading of the fiber. Nowadays, Yb-doped fiber lasers have been scaled in power to above 3kW with near-diffraction-limited beam quality.
High power single mode fiber lasers at the 1.5-micron wavelength region have the significant advantages of eye safety and enhanced atmospheric transmission. This makes them interesting for a variety of commercial, government, aerospace and defense applications. Er/Yb co-doped fibers pumped at 975 nm (where mature, low-cost diode technology is available) has been the standard method to generate high powers in the 1.5-micron wavelength. Owing to the large quantum defect between the pump and signal wavelengths, the thermal load is significantly enhanced which becomes a limitation for power scaling.
The wavelength range around 2 microns (usually как правило Thulium or Holmium doped) is part of the so-called “eye safe” wavelength region which begins at above 1.4 micron. Laser systems that operate in this region offer exceptional advantages for free space applications compared to conventional systems that operate at shorter wavelengths. This gives them a great market potential for the use of LIDAR and gas sensing systems and for direct optical communication applications. The favorable absorption in water makes such lasers also very useful for medical applications. 2 microns fiber lasers ideal for many surgical procedures.
Optromix Company has the unique ultraviolet laser at the 0.257 micron based on 4 harmonic. This type of laser found application in the lithographic processing and for FBG inscription. Optromix Company also manufactures green (515-561 nm) and near IR (770-790 nm) fiber lasers based on the second harmonic.
Fiber lasers are useful because they tend to be stable and easy to use, produce high-quality beams, can emit at high powers, and are easy to cool. Placing a suitable gas inside of a hollow optical fiber allowed the researchers to create a fiber gas laser with mid-IR emission between 3.1 and 3.2 microns!Lasers are central to thousands of consumer, industrial and scientific products; the uses for each type of laser depend on factors such as power, beam quality, and wavelength.
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