Advantages and applications of fiber lasers

As the third-generation laser technology, fiber lasers have achieved 10,000W output power due to the use of double-clad bifurcated fibers and high-power multimode semiconductor diodes. The application range has broken through the narrow optical fiber communication network. It is used in laser processing, laser medical treatment, etc. The industry has become increasingly widely used.

    Fiber laser has the advantages of absolute ideal beam quality, ultra-high conversion efficiency, completely maintenance-free, high stability and small size, which will have a huge and positive impact on our traditional laser industry, thereby rewriting the historical chapter of optical applications.

    In the late 1980s, Polaroid Corp. (Polaroid Corp. Cambridge, MA) and the University of Southampton in the United Kingdom developed a double-clad pumped fiber laser. In these lasers, a glass layer surrounds the fiber core and acts as a fiber cladding to limit the laser transmission in the ion-doped single-mode core. At the same time, it forms the pump light with the outer low-refractive-index cladding. Mode waveguide layer. This unique fiber design can couple high-energy multi-mode semiconductor lasers into the glass inner cladding, replacing the traditional pumping method of directly coupling single-mode low-power pump light to the single-mode fiber core.

    Today, fiber lasers are composed of a long doped double-clad fiber and a high-reliability, multi-mode, single-emitter semiconductor laser, which provides pump light for the fiber cladding. The lifetime of these semiconductor diodes with a single light-emitting structure is 10 to 100 times longer than that of semiconductor diodes with a row structure, which is the key to high reliability and maintenance-free operation. At present, the semiconductor pump laser used in communication products based on the same reliability design tested at 5W and 25 degrees room temperature shows that the MTBF value exceeds 200,000 hours. In addition, compared with other types of same power single-mode (TEM00) lasers, fiber lasers have unique advantages, especially in industrial applications. Mainly include: high wall plug (power supply) efficiency, compact design, easy integration of light transmission and cooling systems, and maintenance-free operation that can provide up to 10,000 hours of continuous light without any human supervision.

    The fiber laser consumes only 1% of the electric energy required by the lamp pumped laser, and its efficiency is more than twice that of the semiconductor pumped solid-state laser (Nd laser system). The combination of higher efficiency, longer service life, and less maintenance makes the cost of fiber laser owners extremely attractive. Fiber lasers are very useful in laser applications that require high near-infrared beam quality. They will have special interest in small focused spot and high power density, such as desktop production. A beam of 100W laser output spot can be focused to as small as 5um, which is equivalent to a brightness of 109W/cm2. The current application positioning of fiber lasers includes: selective welding, marking, various artistic imaging, annealing, bending of micro-mechanical devices, and cutting of 1 to 2 mil stainless steel parts.

Marking application

    The fiber laser marking system occupies a small space and is completely maintenance-free. The excellent optical mode quality of fiber lasers is particularly suitable for high-precision marking applications. The single-mode fiber with beam collimator and the integrated optical focusing system provide an easy-to-integrate beam delivery system up to 7m.